What chamber to order for Nelson or Marvel, standard or Bullseye

First topic message reminder :

I am putting together a bullseye gun and wondering if the tighter bullseye chamber will be a problem with my Federal Auto Match, CCI Target ammo? I have had problems with my Clark 22LR Barrel on my Smith 41 not able to shoot a full 900 without problems. I am thinking of going with Nelson's standard chamber but would the Bullseye chamber provide smaller groups using the ammo I have. I am not a good enough shooter to buy Eley or other top notch. What is your experience with the two? Thanks Tod

I know this is a few months old already but i would like to thank all of you. Oddly I am having the same issue with my model 41 and am looking into getting a Nelson conversion in hopes to improve both my 900 score simply by not having malfunctions and improve my trigger operation on a 1911 as I seem to be not so good at 50ft with a 45 nevermind 50 yards.

I had my 41 relined by Ten Ring Precision via KC Crawford. They use a Bartz chamber. I have run CCI SV, Eley Bullseye, Norma Match, Aguila SE SV and S&B. Only issues was with S& but that is expected. Stuff is caked in wax all the way down the case.

Thank you.

Just 2 cents I found at a Holiday Inn Express last night.

Here is a B-8 x ring from 25 yards I shot from my Nelson (from a rest) with bullseye chamber a few weeks ago.  This is from a conversion built Dec 2021 or there abouts.  This is a repeatable result.  Using CCI SV.


Certainly happy with that for the price they ask, but I am new to the bullseye game.

The one complaint I have though is the slide stop lever had a small raised ring on the back side that scratch the frame of my lower.  A little bit of file work solved it but I did not notice it till the damage was done.  Also the tooling marks on the outward facing side of the slide stop are horrendous. 

Miguel

I am not as experienced in Bullseye Pistol as many of the posters, but I would go for the chamber that provides the highest level of feed and extraction reliability, which would be the larger reamer. 

The ultimate level of accuracy a shooter receives in a rimfire firearm is totally dependent on the quality of the ammunition, all things being equal.

I have talked to two individuals, one a gunsmith at Clark Custom Guns, and another who knew of a custom M41 barrel maker.  Clark claims their M41 smithed pistols will average around 0.75 to 1 inch with match 22 ammunition at 50 yards.  Their guarantee is that it will hold the X ring. The best ten shot group the gunsmith shot was 0.4 inch at 50 yards. That could have been a statistical aberration. The custom barrel maker expressed that 0.75 inches at 50 yards was a good barrel. Since the X ring in Bullseye Pistol is 1.695 inch, everyone ought to be shooting 100 -10X all the time, and consider themself a failure if the score is 100-9X!

In my experience, good match ammunition will hold half an inch at 50 yards  all day long in a rifle

I have tight rim fire chambers in a couple of rifles, and they are both finicky on feed and extraction. The Volquartsen barrel on a 10/22, I can't extract an unfired round, the chamber is too tight. That is an aggravation.  One Anschutz has an extra tight competition chamber and a custom barrel, and a fat round requires an extra push to chamber.

 I do not want a tight fit anything with a semi auto pistol as alibi's ruin scores.