Several months ago, I purchased an unused, still in the box 7mm TCU barrel from Ed's. Recently, I received my long awaited G-2 frame. The trigger is pretty sucky, and I am consulting with Mike Bellm seeking parts, etc. to correct that. Initially, it seemed like the gun was shooting some decent groups. However, I was moving the sights around, trying a couple of different things and trying to get used to the gun, so it was a bit hard to tell for sure. Now, it seems like it won't group very well. About an inch, or possibly more at 25 yards. The shots in each group vary horizontally and vertically. The only loads I've shot have been 24.5 grains of 748 under a 140 grain Remington SP in new brass - fire forming loads. Is the poor performance likely due to the fact that this is virgin brass, or are there other problems that I need to address? - besides the trigger. Any guidance would be appreciated. Thanks in advance.

It could be a number of things. First, what is your shooting style, and is there anything contacting the butt of the grip during recoil?

Secondly, using your FF brass, assemble some loads using H335 and the Nosler 120 grain BT, one of the most consistently-accurate bullets in this cartridge. That being said, though, I have fired many MOA groups when fireforming.

Lastly, your load is very mild, and given the weight/length of the bullet, may not be fully stabilizing at the velocity you are getting.

Oops...one last thing: are your sights secure?

Other things to check that I forgot in the first post include the barrel-to-frame lockup (a Bellm pin works wonders) along with the condition of the crown.

I think you will find as you increase your load by a grain or two your accuracy will improve. I went through the same thing with several 7TCU's, and they all came alive right around 26.5 to 29gr of 748, with 27gr seeming to be the magic number for anywhere from 120gr Hornadys up to the 154 Hornady. Your mileage may vary, but has run me to many 40x40's. Good luck. Russ

Also check your oal - They are probably still using the same reamers they always have and I bet you have a fairly long throat.

Even with the long throat, my 10" 7tcu is the most accurate bbl I have. 26.0g of H335 with 140g Hornady Flat base spire points is the load I use for ihmsa. My oal is 2.700" - yours may be different but try one seated this far out and see how the action feels when it closes..

Hope this helps.

Nate

Rich-
In the small-capacity centerfires which use small rifle primers, I ONLY use Rem 7 1/2s, which seem to be more adapted to the pressures generated and offer a more realistic barometer of pressure (although I would never rely solely on primers to interpret pressure).

About the primers - good question. I believe that I am using CCI 400 primers. The powder weight may be low, and contributing to the probelm. Published data for load info has been hard to come by, and I am nervous about going with max charges in new brass. I hope to fire form another 50 rounds tomorrow and have an even 100 empties to reload with more serious charges. Any recommendations about sizing, etc..?