JackD

I always make a point to read net posts about cleaning 10/22 rifles. I, too, used to be pretty casual about cleaning my DSP, until I experienced a slam fire.

Not long after I installed a Green Mountain Sporter barrel, I was in the process of finishing up a bulk pack of particularly filthy Remington Golden 22’s. On the second shot of a full magazine, a cartridge fired prior to completely entering the chamber. The case ruptured around the rim. The bullet was lodged in the bore several inches ahead of the chamber, and the extractor was blown off the bolt. I got a little bit of powder spray in the face, but was wearing shooting glasses, so it was no big deal. I was also lucky in that the extractor spring was still in the bolt, and the extractor was lying on the bench below the rifle. There was no other damage.

I removed the bullet from the barrel, reinstalled the extractor, and thoroughly cleaned the rifle. I have not experienced a repeat after several more bricks of ammo. But, I do make a point of wiping out the barrel, especially the chamber, on a regular basis. I also make a point not to shoot Remington Goldens in my semi autos anymore.

Why the slam fire? Well, I think the GM barrel has a pretty tight chamber – tighter than Ruger barrels; the cartridges being used produced a lot of fouling; and I let the rifle get so dirty that the cartridge in question didn’t seat in the chamber. The impact of the bolt on the case head fired the shell. There was no firing pin dent on the case.

Please don’t infer that I think that there is anything wrong with the GM barrel. It is an excellent shooter. I just wipe it out with a couple patches of CLP after every brick and it continues to work great.

This phenomenon was also described in a 1994 Gun Digest article by C.E. Harris, “Make an Accurate 22 Semi-Auto.” In Mr. Harris’ case the rifle was rebarrreled with a SAAMI-dimensioned match chamber.

Iowegan

JackD, I too have a Green Mountain barrel on my 10/22 with a tight chamber but haven't experienced a slam fire .... just had problems with the Remington Golden Bulk packs not fully chambering. Upon closer inspection, the Remington bullets measured up to .002" larger in diameter than my CCI Mini-Mags, which chamber just fine. After buying a couple of 550 round boxes, I didn't want to trash the ammo so I made a "die" out of a section of a 22 LR barrel that I had cut off on another project. I reamed one end to the Bentz chamber spec and the other end .001" tighter. I can test each cartridge and if they won't fit in the Bentz end, I push them in the tight end to swage the bullet diameter down. All it takes is grabbing the die and pushing the case head against my work bench then use a punch to push the sized cartridge out of the die. After the bullets are sized, I test them again in the Bentz end and put them in a marked box. At the range, my 10/22 digests the sized bullets with ease .... no malfunctions thus far, except for a few duds, which is very normal with these el cheapo Remingtons.

BTW, I sorted out a batch of the Remington cartridges with oversized bullets and tried them in my Single-Six Convertible (.224" bore). They actually shoot quite a bit tighter groups than premium ammo. Still get a few duds per hundred though.

Here's my home made die:


The left side is the "sizer" and the right side is the Bentz chamber (both shown with a cartridge inserted). The punch was made from a cut off leather stamp tool.

JackD

Thanks for the reply, Iowegan. It never occurred to me that “fat” bullets may have contributed to the problem. This is a first for me. I am curious now – will be measuring some this afternoon.

Re your "die": neat tool. I envy your machine skills.

Iowegan

JackD, Pull your barrel off and chamber a variety of ammo brands. If your tests echo mine ... you'll find the Remingtons won't chamber without force and some won't even chamber with force. You will need a cleaning rod to push the cartridges out. CCI Mini-Mags and Winchester Silver box ammo chamber just fine. Most Federal bulk pack ammo chambers OK but now and then you will find a fat bullet.

At 50 yards, the Remington ammo grouped pretty good but at 75 yards or farther, the groups scatter much more than CCI Green Tag or Mini-Mags. I ran some test batches over the chronograph and found out why. The max velocity spread with Remington Golden Bullet ammo is way over 150 fps (fastest minus slowest in a 10 round string). CCI Mini-Mags and Green Tags run about 50 fps spread, however Green Tags are "standard velocity" so they run about 100 fps slower. The farther the distance, the more max velocity spread affects the group size. I also noted with the Remingtons .... most went "bang" but some went "pop". In other words, you can actually hear the difference in the report, indicating a considerable change in velocity.

I bought some match grade Wolf 22s and tested them. Nice tight groups at 100 yards with my custom 10/22 ... just a tad better than the CCI Mini-Mags but way more expensive. If I were going to shoot in competition, I'd spend the extra $$$ and buy Wolf ammo. Unlike the cheap crap Russian made Wolf centerfire ammo, the Wolf match grade 22s are made in Germany and use VVH powder.

Here's my 10/22. It has a Fajen stock, Green Mountain 20" .920 barrel, some slicked up innards, and a Barska rimfire 3x9 scope.