Compensators

I acquired a Volquartsen Scorpion with all the bells and whistles, including a compensator. Are they allowed in NRA and CMP sanctioned matches?
I read that those are difficult to maintain but I don't understand why they are so prone to accumulate lead. Is there some trick to limit that?

Lead gases condense within the compensator.

My reading is comps are cmp not ok. Not sure on nra.

As to leading maybe keep some clp on it so it doesn't stick or get as hard? The old high standard comps* came with a scraper tool but I'd be careful scraping against aluminum.

*Gilbert Hebard tested these and they diminished accuracy.

Since Mr.Hebard's tests, some measure of technical development may have improved their efficiency, I don't know. Has anyone here run their own tests?

It wasn't here, but I have read a post advising to dip the whole compensator in CLP. This seemed ludicrous. Is it?

45-50 years ago I shot a lot of High Standards.  With and without comps. 
Comps affected the accuracy.  The comps that mounted more out of concentric with the bore (seen visually) expanded groups the worst.  One comp-barrel combination I had was very concentric looking through the bore at a light.  It shot the best of the comp trials.  But not as good as no comp. 
That all said you must consider having a good barrel in the first place.

Happy to be proven wrong, but isn't that gun and it's compensator simply "aping" the Open Class "Race" guns used by the Run & Gun crowd? I guess that there is a proven case with high energy 9mm/38Super/40S&W where a compensator can hopefully reduce sharp recoil induced muzzle flip - but on a 22?

Just a fashion accessory - IMHO. But I agree that they do look cool!

What's run & gun?

Practical pistol shooting sports. IPSC, IDPA, Steel and others. Much more popular than Bullseye. Probably much easier and definitely more widely attractive at entry level, but I guess that the top level shooters and their equipment are pretty special.

I am certainly not an expert or even knowledgeable. It is a completely different game. Not my "cup of tea". But no disrespect intended, either.

Barrel weights seem more effective than compensators on .22 pistols and without any degradation of accuracy. I'd just shoot without it and keep it in case you ever sell the pistol.

The Steel Challenge type matches seem to draw at lot of 22 comp pistols. 8" - 10" plates out to maybe 50 feet or so. Extremely quick shooting where one's reflexes are put to the test and 18 year old shooters are getting a little long in the tooth to be a national champ.

take a look at Jim Clark sr,s ruger he used back in the day when he won the  at camp perry.he built comp into the end of his ruger 22. very accurate. screw on not so good.

hotshot9 wrote:take a look at Jim Clark sr,s ruger he used back in the day when he won the  at camp perry.he built comp into the end of his ruger 22. very accurate. screw on not so good.

Jim also built compensated 45's. I had one of his with a tapered cone compensator. He also shortened the side back to about commander length so the pistol was about 5 1/2 inch slide plus comp. Very accurate.

thats a new one on me! never herd of shorted slide with a comp gun. never saw it on a 45. ultra cool!

How I understand it now is that if the comp is ever so slightly misaligned with the barrel, it will scrape the side of the bullets and the resulting lead chips are the stuff that accumulates in the comp.

I had never shot a pistol with a comp before, and I like how the recoil feels on this gun compared to my Mk III 22/45.
I'll keep on shooting the scorpion with the comp until I get familiar with the gun and then remove it, to see if it changes anything.

I have also been looking for barrel weights since the pistol is so (too?) light. The ideal would be a picatiny-compatible weight, but I couldn't find anything.
I was thinking of 3D-print something and fill it with .45 bullets, but I have not solved how to attach it securely.
I would be thankful if you could think about something that would do.

The three comps I had, Jim Clark, Wilson Accu-comp and a Alpha Precision 38 Super all would have a solid lead coating inside the comp. Once it was thick enough it would start to crack loose and you could pop it out with a metal pick. I would think if the bullet is hitting the comp that comp would not be on the barrel very long.

I have dabbled some in the "run and gun" stuff years ago.  The only advantage I saw was that when trying to shoot major power factor with the 9mm or 38 Super comps helped reduce the muzzle flip.  When I say major power factor it is a formula where the weight if the bullet and velocity have to be boosted to reach a certain number.  Some of the run and gun associations use a scoring system where when shooting major power factor you get a higher score than when shooting what we would call mouse loads.  It is all very "complicated". (Pun intended!)

In tbe 70s i shot a smith 7 3/8" 41. Tried the comp for quite a while until i got around to testing verses it verses no comp..  BIG difference and no it wasn't off center to the  bore. Filled with lead no matter what..

I have personally shot, literally, hundreds of thousands of rounds through compensated barrels in 9mm, .38 Super and .38 special. If they are done correctly and if kept clean enough, they do not effect accuracy. You can shoot more rounds with jacketed bullets than with lead before they load up. The HiTek coated bullets are some where in between. How hot the load is, and perhaps how hot the powder burns may also have an impact. Last, the port designs, and the exit hole has a bearing. The above guns had .370 - .380 bore holes in the comps.  ( Note: Hollow base WCs in .38 spl may be negatively impacted by comps)

To help keep the comp cleaner, start with a very clean comp. Minimize scratches inside, as that gives the crud a place to cling. Wipe with oil. Many, after a 40-50 shots, give the comp a squirt of a lanolin based brass lube (Dillon spray pump bottle) pour excess out. This reduces buildup, but does not eliminate it. If you shoot guns, they get dirty, Clean them.

I do not have experience with comps and .22s. I believe they were quite popular among the International Rapid Fire crowd some decades back. They use a mixture of hydrogen peroxide and white vinegar to dissolve the lead. How toxic this is, I do not know? My guess is that it is quite toxic.

As for accuracy. Don't some of the best air guns in the world have compensators? Aren't they credited with ultimate accuracy, and they have the smallest diameter bullets? I would think that should bear proof that compensators, if done correctly, do not have a negative impact on accuracy. Do air gun comps lead up? I don't know. If not then, the build must be caused by burning propellants, not just lead.

Downside of a comp on a 1911. You will either need to run a hotter load, or drastically lighten the recoil spring, or it may not run. If you have a slide mounted scope, the problem is compounded even more. Example. In a typical 5" 1911 with target velocity 9mm or .38 Super loaded with a 115 gr bullet running 1100-1150 fps a 13 - 16 lb recoil spring will work fine. Make no other change except add a comp to the barrel, even if the comp is aluminum or titanium, and that recoil spring will need to be reduced to 6 - 9 lbs or the gun will not run. The comp, when gun is fired adds downward pressure on the barrel. That is good for reducing muzzle lift, however, with a 1911, when it unlocks, the rear pf the barrel must drop down, meaning the muzzle has to point upward. The comp keeps the gun locked up, by keeping the muzzle down. A hotter load, or weaker recoil spring will cure this. The brass trickles out of the ejection port.  Another down side is noise. They are much loader. Another,  if shooting under a covered firing point they may shake debris to rain down on you. And another, in some States a threaded barrel, may make it fall into a taboo category.

I have been following this thread but decided to wait until my pistol was finished to post. This is my new 38 Super with 1:10 ultra match barrel. I had a choice of threaded (50.00 extra) or plain. I went with threaded. I can always take the compensator  off but can't try it if the barrel wasn't  ready. The barrel came oversized and I slowly made it fit. Going to be another fun project finding the perfect load. 500 new Starline brass showed up FedEx today so I better get to work.

LenV,

So with the 1:10 twist, my guess is that you were thinking heavier bullets, travelling slower, instead of the typical 115-125 gr bullets running a little faster? I have used comps with "slower" loads in .38 spl revolvers with 138-158 gr bullets in the 800-900 fps range as well a lighter bullets 110-125 gr in 1000-1100 fps range. Of course comps on 9mm and .38 Supers from 115 -125 gr bullets in 1020 -1180 fps range too.

In my experience, if a comp is used with slow moving bullets, I got best results from an accuracy standpoint with a short comp. With faster bullets it doesn't matter as much about the length of the comp. I am speaking about accuracy, not so much about how efficient or effective the comp is. Port design, probably matters more in that regard, as well as powders. I am not an engineer, nor scientist, but my opinion based on my experiences and trying a bunch of different stuff is as follows.

Given that a heavier bullet of the same caliber as another bullet, then it likely is also longer than the lighter bullet.

Given that that once the bullet has left the rifling of the barrel you don't want it to touch anything until it reaches its target.

Given that once a bullet leaves the rifling, it still can be effected by touching the comp until it exits the comp. Think of a barrel with a comp, as having the effect of more than one exit hole. It will have at least two, and maybe 3-4 exit holes aligned with the bore.

Given that a slow moving bullet is subject to being effected over a longer period of time, compared to fasting moving bullet travelling the same distance. Bullet hitting one of more comp chambers after leaving rifling, but before exiting final "muzzle" hole.

I believe the slower moving, heavier, longer bullet, has a greater likelihood of touching the comp than does the faster moving shorter bullet. This is the only explanation that I could come up with regarding long comps and heavier bullets, losing accuracy over a the same load with no comp, or a short, one port comp. Put another way, follow through will be excessively important. 

Keep us posted on your findings.

My 52 keeps me honest on follow thru. You are correct. I have 147 and 130gr SWC I plan on working with. Plus the 1200 or so 125gr JHP I already have loaded. I will keep you posted.

Here are various comps for slightly different applications. Top photo and 3rd gun from left is very different. The comp is not mounted to barrel. All others have comp threaded onto barrel.

hotshot9 wrote:thats a new one on me! never herd of shorted slide with a comp gun. never saw it on a 45. ultra cool!

Springfield Armory sold one like that probably in the late 80' / early 90's.  They had a catchy name for it IIRC.  A couple of my friends had bought them back then.  Both used them for Bullseye but neither guy was a serious competitor so I can't really speak to their results.

John,

On the top photo, and 3rd gun from left in other photos I just posted, that gun has a commander length slide, yet a 6 1/2" barrel. The barrel obviously then extends well beyond the end of the slide. The bushing in that gun is relieved around the barrel, so it does nothing except retain the recoil spring plug and spring. The front lockup in that gun is within a radial collar just aft of the comp. It was all custom done to achieve desired objectives at the time. 

The one of a kind stainless steel shroud does 5 things. It acts as the scope mount, it encapsulates the slide for barricade shooting, it gives the "wings" a mounting platform, it contains the collar which has the proprietary bushing for lock up, and it holds the comp. The gun is incredibly accurate and reliable. Four downsides. It  is very heavy, the SS shroud gains heat and keeps it. It is one of a kind, so anything that breaks, will be expensive, as was the gun when I had in built 20 years ago. Last, it slings brass into the next county. Not good for salvaging brass, nor for competitors, if any shooting to one's right.

I built this gun for Bianchi. I have only ever shot one 1920 in the COF during a match. It was done with this gun. A few 1918's but only one 1920. All of the guns in the photo are Bianchi specific guns except the STI with poppel holes, which is an IPSC/steel platform. I also have 4 revolvers built as Open Guns for Bianchi. They are fun too. Only one has a comp.

Thought some of you might be interested in the results of a rather famous "compensated" 45.