Thread: .22TCM Micro Varmint rifle build

Before grouping I wanted to address the brass necks a little more. The Armcor Precision co brass was fairly roughly cut on the case mouth and lengths varied quit a bit which wasnt helping when trying to seat flat based projectiles concentrically. One in three loads had a wobble when rolled on a flat surface.

So I quickly spun up a case OAL pilot for a lee cutter to cut all the brass to the same length and square them up. A quick case harden and I put it to work. they were then all followed up with a chamfering tool and they look and load way better.









I loaded 5 rounds (all now concentric) with 13gr of H110 and headed out in the sunshine on the bench.





I bore sighted it on an object at 50y then put 5 on paper at 100y. They hit 5" high of the bore sight so not bad
The group shows real potential but the deviation/extreme spread was pretty crap.

FPS= 3076, 3111, 3106, 3164, 3111

Now this could be the primer, powder or just the variation in the new brass and may get better after fire forming. Still it has given me a benchmark to tune from.



The two separated point of impacts could have been me with a 7X mag scope, but Im willing to bet its one or more of the things I just mentioned or the fact the barrel doesnt quite have enough clearance at the front of the fore end. I could feel it knocking when I moved it on the bipod and separate group clusters like that often point at bedding. Ill need to run a few more groups to figure that one out.
All excuses aside its a 3/4" group CTC and Ill take it..



I didnt want to inlet the stock any more as it was set up for my trueflight barrel on the 6.5 grendel and this is only a test barrel at this stage. I might have to give it a slight skim down in the lathe to give it a touch more clearance.

Ill fit a 10X scope to it tonight too and shoot off my front and rear bags in future for potentially better accuracy results.

So after some promising results with H110 I shot into town to pick up some Lilgun as Ive read its the go to powder in hornet at the moment and found some mentions on forums of guys using it to load for their TCM pistols.

I looked up Hodgdons data for Lilgun in .22 K hornet as I did for H110 and got the min load of 12.5gr and a max load of 13.5gr. I dropped 12.5gr in and headed out to the chrono... then all hell broke loose.. 3328fps





I thought all was well as it was a light starter load according to Hodgdons Hornet data and I didnt even know it had blown a primer pocket until I lifted the sticky bolt. The pocket has stretched big enough to fit a large rifle primer! The tough little Mauser action did its job perfectly and vented the gas through the actions relief hole and I could trace the sooty gas trail across the various steps and machined faces designed to keep the shooter safe in a burst primer scenario such as this.
I cant quite work that one out as H110's pressures and velocities aligned perfectly with their data but will try again tomorrow from a start load of 10gr of lilgun.

I really want one now

I like this thread, I've been playing with sub cals fro a number of years, with a couple .17 hornets a .17 fireball and a 20 vartarg at present,
I had similar problems with little gun, very erratic in my experience, also with a CZ,
I think you should take a look at blackout, as a powder, this has worked fantastic for me, in both .17 hornet, 22 hornet and .221 fireball.
Ive got my eyes on a cooper in 218 bee, that's been for sale in Alberta, for quite a while, must be close to the same performance, as your little, .22 TCM.

Originally Posted by berg243

big question is will they work good in an 12inch barrelled ar15?.thinking this would be a good goat rifle for easy carry.

Yes there are some AR15 .22TCM conversion in the states with good results.

Are there any rifles primo for an easy conversion?

Id say anything with a .223 sized bolt face. I need to try feeding them from an internal mag such as Rem 700 or Howa. The CZ 527 or Brno Fox works perfectly with the controlled feed but I will need to make a plastic spacer block for the rear of the mag and a new shorter follower or import a .221 fireball mag for it..

I loaded some more Hodgdon Lilgun loads today, the start load of 10g.. no blown primers today.

10.0gr = 3034fps
10.5gr = 3069fps
11.0gr = 3144fps Flat primer with cratering

Im going to call 10.5gr my max load in this barrel. Ill load 5 more up and check the ES when I get a moment.
I have ordered some Alliant 300MP to test too (thanks for the heads up on that one @R93 )

I have decided not to waste time on this barrel chasing accuracy etc, it has served its purpose other than the shortening length tests which Ill get to in the next few days too.

I have made a start on machining a Shilen 1-14" twist barrel for it tonight which I think will get slightly higher velocities with less pressure and will be better to test accuracy with.
Looking at the velocities in the Remington barrel with 3 different powders tells me Im getting an average maximum velocity with the 40gr Sierra Blitzking off 3000fps(ish) with the 22" 1-12" twist barrel but Id really like to go shorter with the Shilen. Cutting an inch at a time off the test barrel should help me decide but Im leaning towards a 20" now.

this is getting really interesting . . . look forward to seeing how the Shilen goes.

the Shilen i have, 1/14 twist in .22 VarTarg Turbo is a gem .. . shoots the 50grn. VMax into tiny clusters and punches way above its weight.

R.

lil gun sure has been a scorcher and given you the case capacity you desied...I use it in the 7.62x39mm but havent pushed it or chronied it...it goes bang and stuff dies.

Very cool

Originally Posted by Wingman

So after some promising results with H110 I shot into town to pick up some Lilgun as Ive read its the go to powder in hornet at the moment and found some mentions on forums of guys using it to load for their TCM pistols.

I looked up Hodgdons data for Lilgun in .22 K hornet as I did for H110 and got the min load of 12.5gr and a max load of 13.5gr. I dropped 12.5gr in and headed out to the chrono... then all hell broke loose.. 3328fps





I thought all was well as it was a light starter load according to Hodgdons Hornet data and I didnt even know it had blown a primer pocket until I lifted the sticky bolt. The pocket has stretched big enough to fit a large rifle primer! The tough little Mauser action did its job perfectly and vented the gas through the actions relief hole and I could trace the sooty gas trail across the various steps and machined faces designed to keep the shooter safe in a burst primer scenario such as this.
I cant quite work that one out as H110's pressures and velocities aligned perfectly with their data but will try again tomorrow from a start load of 10gr of lilgun.

I had that once man it gives you the shits, had loaded up 100 rounds of 308 for a competition, and went out to practice the day before. Fire five shots all good but I decide to do a few more though. Carry on then wham, puff of gas in the face and bolt wont open. Go home, get it open but the case still there, primer smeared all over bolt and action. Turned out Id mixed rifle and pistol primers in the hand primer. Rapid bullet pulling , depriming and reloading till the wee hours. Neednt have bothered got horribly outclassed and finished just about last as I was still uncertain about the ammo.

Originally Posted by Wingman

Id say anything with a .223 sized bolt face. I need to try feeding them from an internal mag such as Rem 700 or Howa. The CZ 527 or Brno Fox works perfectly with the controlled feed but I will need to make a plastic spacer block for the rear of the mag and a new shorter follower or import a .221 fireball mag for it..

Well considering what you said at the start with them feeding from a 45 mag, could you adapt one of them ala the delisle carbine into the housing/magazine?

Originally Posted by csmiffy

Well considering what you said at the start with them feeding from a 45 mag, could you adapt one of them ala the delisle carbine into the housing/magazine?

The possibilities are endless.. 45acp would be to short for my set up as Im loading the balistic tipped varmint bullets long as Im not restricted to length. The factory TCM pistol rounds are loaded with a very short rounded soft point like a traditional .22 hornet bullet so they can fit in the pistol mag, there is also a TCM9 which is seated even shorter for 9mm pistol conversions.

Im just finishing up my Shilen barrel now and will test the previous loads in the slower twist. Im considering cutting the throat a bit deeper on this one for a longer COAL as my mags dont restrict it. It may claim back a little more case capacity and velocity too.




instants by jorge luis borges

Fair enough. Good intel though