Discussion regarding rifles chambered in 22 TCM
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By wood chucker
#14971 Would you trailblazers like to try an experiment for the rest of us ?
Try backing the velocity down 100-200 fps from max to see if the groups tighten up like they tend to with the .22 Hornet.
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By dungheap
#14972 With all the lightweight bullets I tried behind LilGun, performance was best with a nearly full case and the groups were much larger with lower charges. Several powders seemed to yield same size groups from start to finish, and I gave up on them due to much lower velocities. That being said, every gun has its own appetite, and what happened with mine may not happen with yours. I'm dealing with a 9 twist; the slower twist barrels may perform a whole lot differently. Experiment!!
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By MK111
#14973 I also have a 1-9 twist barrel on my 22 TCM AR rifle. When I get max velocity I'll back off couple 100 FPS and do a test. That is if I remember. But the back off test will have already been done working up to max case loading.
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By MK111
#14978 I got my order of 500 34 gr HP bullets in from Midsouth Shooters Supply. What great fast service and shipping. Plus I picked up a pound of Lil Gun powder at the gunshow I was set up over the weekend. I plan to do some test loading tomorrow. Only got couple days before the pre rut bow deer hunting starts so it maybe a slow testing period.
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By dungheap
#14979 Do your AR mags allow a longer OAL than the RIA rifles? If so, you should be able to go around 11 grains or more of LilGun. If not, I'd start lower and work up slowly, around .2 gr increments. If yours is like mine, your accuracy window will be very small. One of those cases where patience is super important.
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By MK111
#14980 The 30 Carbine magazine will except rounds up to 1.670 OAL. The maximum OAL for this AR rifle depends on the shape of the bullet if the bullet hits the rifling. The Hornady 40 gr Vmax I loaded by the design of the long skinny bullet I could seat the bullet out to 1.585 OAL
But it looks like the 34 gr HO bullets are designed a little more chunky it maybe a little shorter. I;ll know tomorrow and do a report.

FYI I use a Lee Presion 4 hole Turret press with a Lee auto powder measure with the auto disk bar. I use a old Lyman 310 tool 'M' die to slightly expand the case mount to seat the bullet. The case is so short and being so high up in the die when seating bullets the bullet would tip and seat crooked. The 'M' die setup stopped that tipping. I use the old Lyman 310 tool 'M' die because the sizing stem is very short. A regular 'M' die sizing stem looks like it's longer than the 22 TCM case.
Been using a 'M' die for loading 223 on a Dillon 1050 press for years for PD shooting.