Switching to Barnes Bullets - Do velocities tend to be up/down with same charge

[300magman]

I'm having a brain fart, I can't remember if velocities tend to go up or down when switching from a conventional bullet (in this case a speer 168gr 30 cal.) to a barnes bullet (168gr ttsx) when using the same charge of powder.

Don't worry I'm not just going to swap bullets without working the load up; and I'm not loading very near to max.

I just happen to know what approximate velocity I want to see and I'm looking for an idea of what powder charge to load up to to achieve it. I have already shot a ladder test with the speer bullet and know exactly what velocities 1gr increments of powder produce.
I will just estimate from that test if anyone can give me the general trend on making the switch to barnes.

(My particular brass's case capacity and the OAL I'm loading too are both significantly different from the book recipies. . .so they aren't accurate at all in velocity prediction for this rifle)

[bullspotter]

I use barns bullets in my 300 ultra, 180 grain. they were longer then the other bullets i loaded for it. The barns book says only use barns data for their bullets. I know they changed the tsx to have 5 grooves insted of 3 from the original x bullets. Causing less drag and fouling.

I would assume they will not act like the speer bullets. Pry will need to start all over. Anouther thing i have noticed is they will really copper foul the barrel make sure to keep it clean. im sure that will vary also.

[mohr308]

I have Barnes TSX in .223 Remington and they definitely are longer than any other bullet I loaded in that cal. Because of the length, Im unable to reach the same velocities with similar weight bullets. On the Barnes website you can get the load data you need!

Here is the 300 win mag data: http://www.barnesbullets.com/wp-cont...WinMagWeb2.pdf

[bfoosh006]

FYI, Solid Copper bullets accuracy can vary greatly just from the bullets seated depth.....

[300magman]

Well, I didn't really get a direct answer; and perhaps that is because there isn't one general trend? . . . I just thought I remembered reading somewhere that, in general, barnes bullets tend to produce more/less velocity with similar powder loads. (all other things being equal)

I feel the need to post the following clarification of my original question (I thought the second sentence should have gotten this point across already, but apparently it hasn't to some people) because of the ripping that I have been taking in my private message box...thank you to "TimW77" in particular for your exceptional and uncalled for skewering


And perhaps I didn't make myself clear. I will be starting at recommended start loads and doing a ladder test up through the range, I was only looking for this info so I could approximate how many loads to make to get close to my target (below max) velocity, so that I don't end up having to break down so many rounds when I done.

(for example if there is an 8gr spread between the min and max book loads and I am loading my ladder test with 2 rounds at each charge in 0.7gr increments - that is 24 rounds total ! Now I know that I am not going for max, so lets back out the top 2 tiers of loads; that is still 20 rounds. But perhaps with a better estimate I would know to leave out another 2 or 3 tiers of loads)

Its not about being cheap, I just hate breaking down loads. However, as the range is a long trip, its better to take more than I need rather than less, and have to come back for a second trip.

FYI, with some of my rifles that correspond fairly well to book velocities, its pretty simple to estimate this . . . I asked in this case because this one rifle/brass combo doesn't correspond well to book (at least it hasn't with the projectiles that I have used so far)

[300magman]

FYI, Solid Copper bullets accuracy can vary greatly just from the bullets seated depth.....

I have indeed heard this before. Luck seems to be with me so far though, as I have always started with the slight jump that barnes recommends, and to this point I have never been rewarded with anything but great results.

[AllenJ]

I can't remember if velocities tend to go up or down when switching from a conventional bullet (in this case a speer 168gr 30 cal.) to a barnes bullet (168gr ttsx) when using the same charge of powder.

Since they started cutting the bands into them I have read that pressures are lower. If this is true then velocity should also be less I believe.

[old roper]

300magman, I understand what your trying to do.

This is from Barnes on seating depth

http://www.barnesbullets.com/informa...let-talk/tips/

I'm not sure how your going to run the ladder test without finding the seating depth first.

[SL1]

300Magman,

You really did not ask a question that can be answered without more information than you supplied. For instance, do we ASSUME you are talking about loading those bullets into a 300 Winchester Magnum cartridge because of your screen name? How about overall lengths? Powder? WHICH Speer bullet?

I took a look at QuickLOAD, using default values, MY guess at which Speer 168 grain bullet, and set a charge of IMR-4831 to give 60,000 psi. Then I substituted the Barnes 168 grain TTSX. The pressure went up to 68,900 psi, mainly because the charge went from 97.6% to 102.7% of the available powder space when the seating depth went up by more than 0.2" with the longer Barnes bullet. Also, the start pressure on the bullet went from 3626 psi to 5076 psi, which will tend to raise peak pressure. Velocity went up by 100 fps.

BUT, if I adjust the seating depth of the Barnes bullet to be the same as the Speer bullet (i.e., much longer COL), then I get 62,800 psi and only a 30 fps increase.

OR, if I go back to the default COL and reduce the powder charge to get back to 60,000 psi, I get a 25 fps loss in velocity from the Speer bullet load.

So, how do YOU want to load these bullets? Constant COL? Different COLs for constant bullet jump? Different COLs for best accuracy with each bullet? What powder are you using? What is your "desired" velocity? What is your barrel length?

Without knowing these parameters, we can't give you a proper answer. And, anybody posting THEIR experiences with such a bullet switch may mislead you if they made different decisions about how to adjust these parameters than you are making.

SL1

[dunerjeff]

I usually had to reduce powder charges when shooting Barnes Triple Shocks due to them having to be seated deeper in the case.I believe that gave me close to the same velocity because of the increase in pressure. As SL1 pointed out.

As for getting accuracy out of them, I always had to have at least a .05-.06" jump to the lands,1 of my .280Rem. (Rem 700BDL) liked a .08" jump. If I were you I would load mt test ladder up with .05 jump on all bullets and load 2 or three with a .02 at the charge(s) closest to your current charge with the Speer bullets. Just to do a quick group comparison.They are pricey bullets and the less needed to find a good load the better.

[300magman]

SL1 Thank you for pointing that out. I should have included "All other factors remaining the same" -> which is still rather vague I guess when you start talking in terms of Quickload, but I was thinking only of a generalization, not specific load advice.
BTW, I used to use Quickload heavily before switching to my new computer, I miss it. It was great for running some "what if"s



And old roper

I'm not sure how your going to run the ladder test without finding the seating depth first.

I'm not quite sure what you mean? I've always had good luck using Barnes recommended seating depth of 0.05
Ladder tests can be run for different variables, in this case I am just doing powder charge. But If I couldn't get any accuracy at any charge I could experiment with seating depth the same way by loading rounds from say 0.01 to 0.1, if I really wanted to see what a wide range of jumps would do.

[old roper]

300magman , If I'd of known that use used Barnes bullets before I wouldn't of asked.