View Full Version : Shock Buffers on non-competition 1911?

April 10, 2011, 08:05 AM
I'm thinking of upping my SA Mil-spec recoil spring to 18.5 lbs and am wondering if buffers would be of benefit or is it just one more thing to go wrong?
So far my mil-spec is functioning reliably with very light ammo (have gone as low as 4.1 grains of Bullseye without a failure. 4.5 to 4.7 grains will probably be my target/ plinking load. I've shot Federal AE and WWB through her with no trouble as well. I haven't tried any SD ammo yet.

April 10, 2011, 08:32 AM
Buffer; for what purpose? For what result?

April 10, 2011, 08:41 AM
They're fine until one comes apart unexpectedly and ties up your gun. On a race gun-fine. Not on a defensive gun.

April 10, 2011, 08:51 AM
Buffer; for what purpose? For what result?

Well now, I guess I should have stated a little more clearly but assumed people replying to the question would have knowledge on why one would use a shock buffer on a 1911. My bad.....

To my understanding shock buffers are advertised to reduce slide beating itself against the frame at the end of its travel. How well it does this and what the drawbacks are is the purpose of my questions. Slopmeno's suggestion that they are better left out of a non-competition gun is probably a very good suggestion.

Jim Watson
April 10, 2011, 08:57 AM
My FLG likes FLGRs and buffers. So I use them in my target guns. Regular inspections when cleaning have prevented nearly all buffer failure related malfunctions. Nearly all.

But not in the Commander that goes to town.

What is your purpose for an overstrength recoil spring? Your range of light target loads to hardball do not call for one.

April 10, 2011, 10:31 AM
Don't really know if I need a heavier spring or not but it seems to me that if 4.1 gr of Bullseye functions ok then the slide will probably be slamming when I start putting something like Hydra-Shocks or Gold-Dots through it.

My thought is that I'm not going to be using 4.1 grains of Bullseye so as long my 4.5 or 4.7 grain loads function ok on a heavier spring then a slightly heavier spring can only help with heavy SD loads.

On the other hand maybe not. 'Tis why I'm soliciting opinions.

Here's a question. What would be a sign that I need a heavier spring? I've seen information that failure to eject properly with hotter loads can be helped by a heavier spring slowing the slide down. Any other indications?

April 10, 2011, 03:26 PM
If you switch from a 4.1 Bullseye load to full power hardball you need to change your recoil spring. The gun needs to be tuned (springwise) to a particular load. You really only need to run a buff if you're blowing through 1000rounds a week in practice and matches. A buff will only break apart and jam your gun if you install one and forget it. You have to change them when they start to break down. Kind of like tires or shock absorbers. They're not made to last forever. A buff will not take the place of the correct power recoil spring. If your gun is throwing brass 20 feet away your recoil spring is weakened. You should be tossing them 6 to 8 feet. (or less)

April 10, 2011, 04:55 PM
I don't think a Shock Buffer is a good idea in a Kimber gun. The slide stop notch is a bit long in these guns and if a Shock Buffer is installed, you can't just pull the slide back to release the slide stop and chamber a round.

If you inspect a shock buffer every time you clean your gun, I believe you should be pretty safe as far as having the Shock Buffer disintegrate. Then again, I am no expert on M1911s.

- Ivan.

April 10, 2011, 08:30 PM
Just to clarify, I'm not looking to shoot 4.1 grains of bullseye. It looks like my plinking/ target load will be 4.5 or 4.7 grains. I started at 4.7 and worked up. Anything above 4.7 was not as pleasing as the 4.7 loads. I then worked down from 4.7 and found 4.5 about equal, 4.3 and 4.1 maybe a bit weak. I'm now looking for the minimum load that the mil-spec will function reliably. I haven't gone the other way much, got as far as 5.5 grains of bullseye but really waiting to get some commercial SD rounds, see how they work and then reverse engineer them for a good practice round.

So, after all that blather, I think I'm past the buffers. I'm not shooting IPSA or IDPA. Of course, if past performance is an indication, I'm going shoot about a thousand rounds before I think about firing a shot in anger but hey, Murphy Lives. I'm still figuring on trying the 18.5 spring (after the break in period) and if that works maybe try a 20 lb. What I want to know are the limits. (basic engineering...zero to infinity)

James K
April 10, 2011, 11:46 PM
Here is something the makers of buffers won't tell you. The Model 1911 is designed so that the recoiling slide bounces off the frame (or to be more exact, off the flange of the recoil spring guide) so that a lot of the energy of recoil is transferred back to the slide on the forward movement.* This makes stripping a fresh round and closing into battery more certain even if the pistol or the magazine is dirty or the round has crud on it.

Buffers "preserve" the frame at the cost of loss of reliabilty. FWIW, it will take many thousands of rounds to harm even the recoil spring guide, let alone the frame, so you swap a theoretical advantage for a real disadvantage.


*Think steel doesn't bounce? Look at one of those gimmicks made of swinging steel ball bearings.


April 11, 2011, 06:57 AM
Agreed, steel is very elastic, but if you could make the cycling NOT bounce, you would be much better off because the first round is chambered without a bounce and is inconsistent otherwise.

Some of use DO shoot thousands of rounds from these guns. The impact against the spring guide isn't the concern. The spring guide is replaceable. The frame is not. The peening of the frame is the bad part and some frames are quite soft. I personally have shot thousands of rounds through guns with the shock buffers and haven't had one fail yet though I know that doesn't prove anything. I also inspect the shock buffer every time I field strip the gun for cleaning.

There are some kinds of wear you can avoid. This is one that you can avoid. Along the same lines, for reliability, it makes sense to put in a fairly light recoil spring to make sure the gun cycles even if the ammunition is lightly loaded, but I still use 18.5 pound for nearly everything.

Of course, your mileage may vary. This is just what I do and why I do it.
- Ivan.

G. Freeman
April 12, 2011, 05:14 PM
I'm still figuring on trying the 18.5 spring (after the break in period) and if that works maybe try a 20 lb.

If your loads work with the 18.5# recoil spring, there's really no need to change to a 20#. 20# seems overkill, since many people actually use the 16# spring for factory loads.

BTW what type of bullet do you use on your reloads? I've been using BE for many years. On all my 1911's, I use a 16# recoil spring. For my 230 gr LRN I use 3.6 gr of BE, on my 200 gr LSWC, I use 3.8 gr of BE. No need for buffers, since my loads are so light to begin with.

April 12, 2011, 10:30 PM
Using an extra heavy spring is not going to help. It will subject the frame and slide and barrel lugs to abusive battering when the slide returns forward and actually cause the muzzle to dip lower when it does. Use a 16 or 17 pound spring. If you want to slow down the slide and gain a perceived decrease in recoil install an Evolution Gun Works firing pin stop. It has a square bottom corner (like Browning's original blueprint specified) and will give less mechanical advantage to the slide when it comes back and recocks the hammer. This will not cause the slide to be slammed forward like a heavy spring will. The part is oversized and will require a little work with a file to fit your slide. It also locks the extractor in place to keep it from moving which will give more consistent ejection. The original military 1911 used this design but the Army asked to have the stop radiused to allow easier loading on an uncocked gun using the slide. Bunch of girly-men.

April 13, 2011, 12:11 AM
There are some kinds of wear you can avoid. This is one that you can avoid.


They're not needed, but reducing wear would be nice. Let me put it another way. If I was buying a 1911, all things being equal, I'd choose the one that had a buffer in it.

April 13, 2011, 05:44 PM
Using an extra heavy spring is not going to help

Interesting. Wouldn't the forward momentum be taken up by the (I'd say bolt face but that isn't accurate in a semi pistol...) ?frame face? striking the brass case?

April 13, 2011, 08:35 PM
The slide stop is what takes the shock of the closing action. Typically the slide stop is very hard steel (hard enough to dull a file if it is a GI Part). The lug on the bottom of the barrel can get beat to heck.

- Ivan.

April 13, 2011, 08:48 PM
Depending on how the barrel was fitted to the slide, but most of the forward motion of the slide returning is taken by the barrel lugs mating up with the slide stop pin. You only need to use enough recoil spring to strip a cartridge from the mag and get it under the extractor and return the slide to battery. Chambering a round eats up a significant amount of the energy of the slide's retrun. (This is why we are always told not to drop the slide on an empty chamber although a lot of people don't believe there is any difference between picking up a round or going to battery on an empty mag.) Using a very heavy recoil spring is used by a lot of guys to cover up problems like a rough breechface or a rough extractor that is exerting a lot of drag on the return stroke. And it usually forces the system to work but with a heavy hand. The thing I learned early in the competition game was that a heavily sprung gun will slow down your split times (between shots) because you have to wait for the muzzle to come back up from the reaction of the frame to the slide slamming into it. It's not much but it adds up. A properly sprung gun will rise, then dip, and then come right back on targhet with the sights exactly where they were if you have a neutral grip and do not try to "muscle" the gun. That is the beauty of the square bottom firing pin stop, it slows the slide on the recoil stroke and then allows the spring to apply just enough force to return the gun to battery without resorting to heavy mainsprings and recoil springs. Browning was a genius.

April 14, 2011, 11:01 AM
Let me second the use of the EGW firing pin stop. It's Brownings original design. It was changed to the radiused firing pin stop in the A1 because soldiers complained about the effort needed to rack the slide.

What the square bottom stop does is decrease the mechanical advantage for the slide cocking the hammer by pushing on it further down, making it harder to do. That causes a slight delay in unlocking the barrel that gets the bullet out before the slide has moved back as much as when a radiused stop is used. Muzzle jump is significantly reduced, putting the recoil more straight back into your hand, so the gun feels like it is recoiling less and it definitely gets back on target faster. It just takes more work to start the slide back in a clearing exercise. But the spring strength and original battering tolerance assumed that square bottom firing pin stop would be used. Ever since the A1 change, things have been a bit harder on the metal.

Light recoil springs are necessary for extremely light loads. I used to shoot cast 185 grain SWC's over 3.8 grains of Bullseye in my Goldcup as a gallery load and as a 25 yard timed and rapid load. If the spring was the Goldcup standard 14 lb spring, the slide would sometimes fail to make it into contact with the spring guide flange. The gun feels very soft and mushy then, and if you limp-wrist your grip even slightly, it fails to feed, so I went to a 12 lb spring and made sure I had a little of that contact. I widened and polished the feed ramp on that gun until it would feed empty cases, and tried springs all the way down to 9 lbs to play with 3.2 grain loads (poorer accuracy) and never had a feed problem other than the limp wrist issue when the load was too light for the spring.

Going the other way, I got a custom mold made for a 300 grain boattail to shoot in the 1911. I put in an EGW firing pin stop and a 20 lb spring, expecting this big boy would need all the resistance I had. Nope. First, I couldn't safely put enough powder in the case to exceed 700 fps. Recoil felt the same as hardball. So, I went back to the standard 16 lb government recoil spring.

BTW, even with both the 20 lb spring and the EGW firing pin stop, 200 grain SWC's over 4.8 grains of Universal still functioned the gun just fine. A standard 1911 normally still functions with 185 grain JSWC's over 4.2 grains of Bullseye (a standard commercial match load equivalent formula). The gun design is very forgiving over quite a range, and sticking with the standard springs and the old John Browning firing pin stop will let you digest a huge range of loads without compromising the life expectancy of the gun.

April 15, 2011, 05:22 PM
Well hopefully Midway will ship my copy of "The Colt .45 Automatic: A Shop Manual Volume 1" someday (it's been a week and they still haven't shipped).

How is the stop fitted? By hand or milled?

April 15, 2011, 06:37 PM
I've always done it with a file but you have to have a steady hand and good eye to make it fit perfectly. The trick is to remove metal equally from both sides so that the firing pin hole remains centered. Just keep taking very small amounts off until it will slide into the recess at the rear of the slide. You also have to ensure that it fits the groove in the extractor which may or may not be the same as the slide cut.

April 16, 2011, 09:14 AM
I did my first one three or four years ago with one of those diamond impregnated knife sharpening plates. This was while I was visiting a friend who's not a tool person and who had no files, but did have the sharpener.

Basically, on either side of center is a step down to the thinned portion like a side flange that slides into the mating grooves in the slide and extractor. It is notched shorter on the left side to go over the ejector in field stripping and assembly. On the ones I fitted, that flange needed to be thinned from the step side, and its width increased by filing the inner vertical side of the step toward the firing pin hole. I did two others that year, but none since. I don't recall if any flange width had to be decreased again by filing the outside of the ledge to get it past the extractor. It certainly could with some part combinations. In any event, you just put some Magic Marker or Liquid Paper on the flange and try to wedge it in. Where it scrapes off will tell you where you need to file on those surfaces.