Forum discussion regarding pistols chambered in 22 TCM
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By 1911SHOOTER
#14314
dungheap wrote:That was the data that ALMOST stopped me from getting into the .22 TCM.


Dungheap,
Sorry, just trying to help.
Blackie
User avatar
By dungheap
#14322
1911SHOOTER wrote:
dungheap wrote:That was the data that ALMOST stopped me from getting into the .22 TCM.


Dungheap,
Sorry, just trying to help.
Blackie


Nothing to be sorry about. My shooting partner subscribes to LoadData and printed that out for me before I went all in on my Savage build, and I almost had second thoughts about doing it at all. That would have saved me a lot of time and effort, but the adventure of it has been pretty much worthwhile. I just wish there was something other than LilGun that really performs (accuracy and velocity) in the cartridge. For velocity, nothing comes close to LilGun; for accuracy, most powders don't seem to deliver very well at all. LilGun is accurate, but it's accuracy node is very, very small.
User avatar
By earlwb
#14419 I used a sheet of paper that came with the cases and bullets for my initial reference point.
I used H110 or W296 propellant like they suggested. But this other data is quite interesting though. I may have seen it before, I forget now though. Thanks for posting it too.

Image
User avatar
By Rangemaster1
#14425 Some interesting observations on reloads vs. factory in my Remington model 7 rifle.

I cut the throat of my rifle for Barnes 36 grain lead free bullets. I added .005 so the bullets were off the lands that far. Factory bullets are .025 short of the lands which means they have a bit of a jump to get there. The little short squatty bullet shape doesn't help a lot. That probably accounts for the poor accuracy from factory loads in my rifle. A rifle that is specifically chambered for the factory round with minimum freebore should shoot fairly well.

My barrel has a 13 twist which is good for most lead bullets up to about 60 grains. I have no intention of shooting anything that heavy, but I could. I may try some 50 grain Barnes Varmint Grenades just to see how they perform. I chose 13 twist in the event I wanted to rechamber to a larger case, i.e. 223 or 22-250. I don't believe I will though. The TCM is too much fun.

Another fun tidbit of interest is the standard deviation of my reloads. They all are in the 18 to 21 range and I mean all of them regardless of velocity or powder charge weight. I don't know if it's the brass or the bullets. I maticulously weigh each powder charge so I don't think that is the problem. The velocities of all my test loads varied by 50 to 65 fps in groups of ten or fifteen. Has anyone else seen this occurring? It was never my intention to go to extremes in prepping brass, but I'm real curious to learn where the culprit is. This week I intend to completely prep 50 rounds of once fired AP brass to determine if the phenom is the brass or bullets. I would like the SD to be below 12.

FYI, the best, most accurate load for the 36 gr. Varmint Grenade is 12.4 gr. Of Lil' Gun at 3327 fps. Less than 1/2" at 100 yds. Not bad for the little beast. Some day I may try some match grade bullets just to see what it will do.

Happy shooting and may all your fliers go in.
User avatar
By earlwb
#14426 I suspect that it is the really small cartridge case. It doesn't hold much powder. Thus very slight changes can result in pressure differences, which of course results in the deviation. But that isn't based on any real data results though.
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By Rangemaster1
#14428 I agree, but the velocity and the SD variations are so consistently the same that it is confusing to me. Wider variations in velocity and SD's would be the norm. They are just too damn consistent.
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By earlwb
#14575 I was thinking that a variation of 50 to 65 fps is pretty good actually. So you may be perfectly fine in this case.
I remember during my fanatical target shooting days, where I weighed and matched everything. Cases, bullets, powder charges. I would use all the same brand and lot cases and bullets too. I even used a razor blade and cut the powder granules down to ensure the powder charge was perfect to less than a tenth of a grain.

So if everything is equal in your case, it may be variations in the cases. Such as thickness from one case to the next. Neck tension for holding the bullets could be different from case to case too.

Yeah the short squatty pistol bullets are not all that great in the rifles. But they do improve more when you slow the bullets down instead of having them go faster. Such as try to keep the bullets down to about 2,000 fps in a rifle for example.
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By Rangemaster1
#14582 I agree that the SD isn't a biggy, it just the strange lack of variation between test loads that has me wondering. I've loaded some test loads where I trimmed and turned the brass. I found the brass to have a diff of up to three thou on a side at the neck. Even stranger is the fired factory load brass I have is averaging smaller neck thickness than the bag of AP brass I bought and have been loading. Their stuff is not very consistent, but ground squirrels won't much care.

Loading for a factory rifle could be an exercise in futility. Although I don't own one, I've done some research on them. The rifle is a redesigned rimfire with a rim fire bolt. The bolt doesn't have a camming surface at the end of the bolt lift to assist in extracting fired rounds. Therefore, rounds are sticking in the chamber and difficult to extract. Factory ammo is too hot for the rifle. Pressure is much too high. A reloader needs to load lighter than factory to eliminate the sticking problem. As you said, keep the fps to around 2000 and that will eliminate the sticking by lessening the pressure factor.