357 mag buffalo bore load duplication.

[Shadow9mm]

Originally Posted by stinkeypete

.357 is interesting to me because it seems one continues to get velocity gains by increasing barrel length even up to carbine lengths.

However, I really enjoyed a review by Jeff Quinn (rip, he was a great guy) of the Ruger .327 Fed Mag where the shorter of his Single Sevens gave higher velocity and the only explanation in those ranges could be variations in manufacture of the barrels. I love/hate extra variables.

I have Phil Sharpe’s book, comments, and load data from the early ‘50s. His comments include warnings that the pressure of .357 is very high and “small” errors might result in danger. Well, this is before things like the Blackhawk in .357.

It just doesn’t seem like the 180 grain bullet is optimal for .357. Just too heavy.

I admit I have done my share of hot-rodded “+p” loads for my guns that I judged much stronger than average. Over time, after succeeding at making some really snappy loads, I realized that .44 Magnum was more comfortable for me when wanting to push heavy lead. Not needing to alway use a huge hammer, something about 2400 and easily found “reasonable” amounts gave me lots of flexibility.

That freed me up to let .357 and 158 grain bullets and lighter to go fast.

Also, to ask myself the question of “why”?

I used to use Lil Gun, and pushed it hard. In the end, I felt more comfortable with .44 as a deer hunting round and I don’t need to push .44 Magnum to get my desired ballistics.

The most important thing I learned from Phil Sharpe is you really can’t tell pressure by examining the case or primer. Or, by the time you can, you are up near “proof” load pressures where danger is very real.

I have shot 44s several times, recently with HOT handloads in a blackhawk. Nothing against them, and the recoils is manageable, I have just really taken a liking to 357s. They tend to be more blast than recoil, and I just find them more enjoyable to shoot. I am hoping to add a lever gun to match but it probably wont be until next year.

I have been reloading for about 15years now, 9mm, 45acp, 223, 308, 30-06. This is my first foray into magnum pistol cartridges and powders. So far I am generally not a fan of light bullets, preferring to stay in the 158 range, with the exception of some of the all copper lehigh bullets. I really like their 120g extreme defenders and I managed to get them up to 1478fps with a max charge of powder pistol from lehighs load data. I tried some 110g sierra bullets, a friend gave me with sierra data for a 5.5in barrel with power pistol. only managed to get 1583 fps of 1760fps promised. 357 seems to excel with heavier bullets. The heaviest I have gone at this point is 165 gas checked SWC that I managed to get op to 1326 with lil-gun. For most of my loads I plant to stay in that 158-165g range, but I really wanted a heavy fast load and buffalo bore fit the bill. I ran across the duplicaiton video and already had lil gun, so I figured I would try a slow and cautions workup to see what kind of results I could get. And hopefully provide some good data so others would not have to repeat my testing if this was something they were interested in.

Bullets came in today. Going to put together the initial test batch from start to max and hopefully do testing the the next week or so. I also have a bore scope, I may try and take pics before and after testing to see if there is any visible change in the cylinder throats, forcing cone, or start of the rifling during testing.

[Nick_C_S]

I'm going to keep this high level and not get in the weeds too much. My opinion will be worth every penny you paid for it . But you said you wanted thoughts. And here's mine, based on 36+ years of loading 357 Magnum . . .

I have no experience with Lil' gun. But I understand it's in the burn rate neighborhood of W296. I have little experience with 180 grainers; but have played around with them a little - but not enough to truly test them all the way up the ladder.

I do however, have a lot of experience with 158 grain jacketed bullets. A lot. And in years of testing, I have rarely seen as much as 1300 f/s through a 4" bbl (model 686) - I'm talking in load work up tests. My top load (not a test load - "regular production," if you will) using W296 yields 1253 f/s though that 4" bbl gun and 1299 f/s through a 686 with an 8-3/8" bbl. I suspect a 6" bbl would yield some velocity in between (1749 f/s through a Henry 16" for those keeping score at home). This loading is an over-charge per any current load manual. It's not a pussycat load - it roars. It's stout.

So when I'm reading this:

The target is above 1400fps. However I have seen velocities in the 1450 to 1490fps range in youtube chronograph testing with 6in guns.

my eyebrows pop up. So I'm just some old guy whose been loading since the 1980's and generally considers top velocity 158's to be in the 1250 f/s neighborhood; and here's a fellow handloader talking about taking 180's to over 1400 f/s. Regardless of what propellant is being used, that gives me serious concerns.

I'm also concerned about the concept of "chasing velocities." When approaching a load work up, my head is never: "I'm going to try to reach xyz velocity." I'm looking for clean, consistent burns that reflect consistency on the chronograph. When extractions start getting sticky and primers flattening, I know it's time for me to stop. The velocity is the velocity. And that's what I get - to take or leave.

On many occasions, I have tried to emulate - not duplicate - factory ammo. I have the factory ammo chronograph numbers (tested through my gun - not theirs). I select my propellant and do my load work up - it either comes up short (often) or succeeds. It is what it is. I never - ever - keep going to reach the factory ammo velocity. Point is, when I'm doing a load work up, I never have a pre-conceived velocity number in my head. That's a good way to put yourself in position for disaster.

Shadow9mm: I hope your work up goes well; and I hope your final results are satisfactory to you. Load safe my friend.

[44 AMP]

I may be a bit overcautious to start, I never load "from start to max" before shooting any of the load, simply on the off chance that my particular may not get to max, and I dislike the idea of having to pull down rounds I've already put together. I will load a small batch at start, and then another above that, then shoot them, to see the results before loading any heavier. But that's just me.

One thing I will not do is load ammo without the gun it is to fired from. EVER.
A few years back there was a fellow here eagerly awaiting delivery of his new gun. He had a bunch of components and dies and was eager to load them up so as to have ammo ready for his new gun when it arrived.

I advised him not to do that. He couldn't wait, and loaded 500 rnds. When the gun arrived, NONE OF THEM FIT. And he had to tear them all down and start over. Things might have worked perfectly, often they do, but sometimes, they don't and you can't know for sure until you have the gun in your hands to check with.

[Shadow9mm]

Originally Posted by 44 AMP

I may be a bit overcautious to start, I never load "from start to max" before shooting any of the load, simply on the off chance that my particular may not get to max, and I dislike the idea of having to pull down rounds I've already put together. I will load a small batch at start, and then another above that, then shoot them, to see the results before loading any heavier. But that's just me.

One thing I will not do is load ammo without the gun it is to fired from. EVER.
A few years back there was a fellow here eagerly awaiting delivery of his new gun. He had a bunch of components and dies and was eager to load them up so as to have ammo ready for his new gun when it arrived.

I advised him not to do that. He couldn't wait, and loaded 500 rnds. When the gun arrived, NONE OF THEM FIT. And he had to tear them all down and start over. Things might have worked perfectly, often they do, but sometimes, they don't and you can't know for sure until you have the gun in your hands to check with.

Unfortunately things are super busy for me work wise. And the range is 1hr away. It kind of necitates loading what I want to shoot before hand. If I have to pull a handful down, its a pain, but I just have to deal with it.

[Unclenick]

It is necessary to buy a Pressure Trace and have a gun, like a lever-action carbine, you can fit the strain gauge on without interference in order to know for a fact what pressures you are working with. If, as Hodgdon does for its data, you are firing from a 10" closed-breech unvented barrel, as an Encore or Contender 10" barrel without a muzzle brake, you can guess something about pressures with velocity data. If you DO have such a barrel, you can tell that if your velocity is lower than Hodgdon's is with the same load, then you have a lower peak pressure in your particular gun, and vice-versa. But how much higher or lower cannot be determined by velocity. Only average pressure down the whole length of the barrel can be deduced from that with any degree of accuracy.

Let me correct a misconception about friction coefficients. By themselves, they do not tell you how barrel friction for different bullets will compare. A friction coefficient is something you multiply normal force by to get the friction force. The normal force is the force pushing the bullet against the side of the bullet (force perpendicular to the bore surface).

Part of that normal force is due to the springiness of the bullet itself. If you have ever driven a pure lead slug through a bore with a rod, you know it only takes hand force once the slug is in the rifling. If you've ever tried to tap a stuck jacketed bullet out of a barrel, you'll know it is very hard to do and sometimes can't be done at all with rods and a hammer, and may require a hardened rod and hydraulic press to do. This is because, despite the coefficient of friction being lower for copper on steel than for lead on steel, the springiness of the bullet makes the normal force of the jacketed bullet much higher, and that much higher force times the coefficient of friction is what the friction value is. Pure lead has almost no springiness, so once it is bore-size, it just glides right through, as its force normal to the bore is close to zero in that instance, multiplying zero times lead's coefficient of friction still gives you a zero friction force result.

The other part of the normal force with which the bullet presses against the side of the bore is due to the acceleration force trying the squash the bullet fatter and shorter. This bulges it out against the sides of the barrel and provides an additional normal force to multiply by the coefficient of friction to add to the friction force number. This force is highest when acceleration is highest, and that happens at the pressure peak. This is why copper fouling tends to be greatest an inch or two past the throat of a rifle: that's where the bullet is when the pressure and, therefore, the acceleration peaks and the outward bulge from acceleration upsetting the bullet is greatest.

That outward bulging is important. Due to the column of mass above it, the bulge is greatest and has the most outward force normal to the bore at the bottom of the bullet and the least at the top. This is why friction is not simply proportional to bearing surface length. The portion due to outward spring is, but not the portion due to acceleration bulging.

To better see this, Einstein's view that gravity is an accelerated frame of reference helps. The force earth's gravity puts on a mass accelerates it at 32 ft/s² near the earth's surface. Bullets accelerate faster than that. In earth's gravity, that accelerating force is what we call the weight of the object. A gun firing with 40,000 psi peak pressure, due to Newton's second law, has "weight" equal and opposite to the accelerating force which is the pressure divided by the bullet's cross-sectional area. For the .357, it is 0.28 times the pressure, or 11,215 lbs that the bullet "weighs" at that pressure peak, less the bore friction, which is usually estimated at around 5% of the total force on the bullet, so the bullet is experiencing about 414,000 gees. If you sat it down on a pate orbiting a neutron star at about 2000 miles from its surface, it might weigh about that much. You can see how, without the barrel around it to hold its shape, such a bullet would bulge outward mainly near the base due to the weight of the column of bullet mass above it.

F.W. Mann did experiments with rifle barrels shorted to around an inch of bore length so the pressure effect could be seen on the bullet because it would emerge from the containment of the barrel while the pressure on the base was still peaking, and with jacketed ones, he got effects similar to this:



In that illustration, where the bulge is widest is where friction would be greatest with the barrel in the bore.

[Sevens]

^^ Exactly what Unclenick is showing here is quite specifically what ballisticians at ATK including Ben Amonette who had been quite helpful via e-mail were explaining to me in two different calibers. Let me explain a little bit.

I had been doing a lot of experimenting in .327 Federal since there was a dearth of both components and load data, and I was playing with the .32 ACP-specific 71gr FMJ bullet. Know going in that a 45k psi max cartridge built around 100-115 grain bullets has the capability to REALLY sling a 71 grain pill.

Also on .460 S&W Magnum where we discussed the huge selection of .45 Colt bullets and why MOST of them are just not appropriate in .460 S&W Magnum, a full 60k psi max cartridge.

Ben explained to me that the extreme pressure pulse on the base of a bullet that was not at all designed to be pushed at twice the speed for which it was intended can, may (will?) distort that bullet and in the passing from cylinder through flash gap and in to forcing cone, the distortion of the bullet (as Unclenick describes above) can and possibly will damage the forcing cone when it attempts to go out-of-round under the extreme pressure.

I don’t believe this will be a specific issue with a 180 grain lead slug in .357 Magnum, but it seems relevant to the conversation.

If I owned a .327 Federal barrel for my Contender, it might be fun to see just how fast I could send a 71 grain pill. WHY? Well, for the same reason that I do nearly all that I do at the load bench and at the range… for fun, because I want to. It would not be subjected to the jump of a flash gap in a revolver.

[Shadow9mm]

Uncle nick, please put me down for 2 copies of your book whenever you write it please.

[Shadow9mm]

Got my bullets in. Started a new thread for a quick review of the bullets here. https://thefiringline.com/forums/sho...57#post6891557

[Shadow9mm]

CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.


Ok, so I was able to get some testing done today. It was a bit quicker of a work up than I would have preferred, and I was only able to do 3 shot groups due to technical difficulties with uneven brass lengths and crimping problems. I did not go over max, I stopped at 15.0g even as I had some sticky ejection and primers were getting flattened. I hope to do it again in the next few weeks.

Brass, mixed 357 mag (I am hoping to source some starline in the near future)
primers CCI 400 small rifle
bullets, Montana bullet works 180g WFN sized .359 (avg weight 187.2g)
Ruger GP100 6in barrel
only 3rnds per group tested

Lil'Gun
13.0g avg 1246, es 73, sd 38.9
14.0g avg 1271, es 83, sd 41.6
15.0g avg 1307, es 14, sd 7

H110 (the sierra data I found listed max at 15.9g with a jacketed bullet, based on ease of ejection and pressure signs I decided to test at 0.1 over max for an even 16g.)
15.0g avg 1242, es 12, sd 6.9
15.9g avg 1331, es 86, sd 43 (crimp problems)
16.0g avg 1332, es 28, sd 15.1


Conclusions
Compring lil'gun to H110.
Lil'gun did leave the cylinder warm after firing, but I would not say hot. H110 did not heat the gun up nearly as much. for a hunting load that I wont shoot rapid and really tear the gun up I don't have an issue using it.

Lil'gun burned a lot sootier

lil'gun had a much more distinct and aggressive crack/report when firing.

throats, forcing come, rifling start all look normal, and I have probably close to 75rnds of full power lil'gun loads through the gun.

Over all l was much happier with how H110 performed. I was dissapointed though that neither powder was able to get up into the 1400fps range, sierra stated 1440 t max with a 5.5in barrel. But for the weight, I am happy being in the 1330fps range. I was able to get 2lb of H110 at the local shop as well as a box of 180g XTP to play with. I will keep the lil'gun on the shelf, but don't plan to use it much in the future.

I hope to do some testing in the near future with both powders and some larger sample sizes, I really don feel that 3rnds is enough.

[skinnedknuckles]

I started down this rabbit hole a couple of years ago but did not go as far as you are contemplating. I looked at Buffalo Bore but it just seemed further out there than I wanted to go. However, HSM also has a 180 gr LWFNGC load called their Bear Load that seemed more reasonable, and I bought some and some Missouri Bullet coated 180 gr LWFN (no gas check).

I got 1182 fps out of my 4" Taurus Model 66 and 1632 fps out of my Rossi M92 20" barrel lever gun.

I started at minimum load of 13.1 gr of H110 (load not from Hodgdon, use at your own risk!). I got 1143 fps in my Taurus and 1571 fps in my Rossi and I called it good. This is a pretty energetic load that doesn't shoot too hard so it doesn't beat me or my guns up too badly. It goes in the Taurus which goes with me when I'm in the woods. Yes, the Buffalo Bore has maybe 200 fps more velocity but I'm satisfied with the HSM level load. YMMV.