Bear Creek (I know...) bolt action upper in 6.5 grendel - New

[grayfox]

Outstanding!

[Dino11]

The issue with this setup is that it uses a standard AR15 bolt. It is not a two or three lug bolt like a true bolt action rifle, you are still limited to using gas gun loadings.

[m796rider]

The issue with this setup is that it uses a standard AR15 bolt. It is not a two or three lug bolt like a true bolt action rifle, you are still limited to using gas gun loadings.

I don't know... a 120gr Match Burner at 2530fps seems pretty useful to me on the 600yd max range at my gun club. I stopped chasing the velocity demon a long time ago.

[grayfox]

I have thought about that also, ie, are the AR standard lugs a 52ksi limiting factor, the weakness as it were?
While I'm not sure that it is a 52 ksi limit, I don't see myself going much above my 18" AR loads (that's where the barrel is beuing donated from) In this case, for this new setup.

In the bolt action setup, if I'm not mistaken, the primary "holding barrier/counter thrust" to the bolt's thrust at firing, is the bolt handle and its "locked" position. The lugs are not bearing the back-force on their own, maybe some of it, but it's not an AR setup, again, if I'm not mistaken here.
The bolt's lugs do not have to twist nor even move at or during the shot/ bullet travel, they move only after all back pressure has been eliminated. The only shearing force they encounter is after the shot, and is the back-force of the spring that BCA puts on the bolt's tail... not very much force at that, comparatively.

[m796rider]

FYI the Amend2 10rd polymer Grendel mags feed like butter.

[grayfox]

First trip out with the BC-15 bolt action upper, and my existing 18" grendel barrel on front. It was a very windy, blustery and chilly afternoon, around 45 DegF. Winds gusting to over 20 mph from the 3 o'clock.
I first re-zeroed b/c took off the scope and back on (but obviously a different upper), 2-3 shots on the 50 yd side.
Then off the the 100 yd part.
I had my 120 Tgk's on hand, some 123 Hornady factory eldms, and a few 129 ablr's in CFE.
The targets didn't look so great b/c of the winds, but in a couple calm spots the 120's were dead on.
The 129's, scattered to ~1.5 moa but I figure because of the CFE and temp variability. So not worried. My go-to for ablr's will be ar comp or xbr (which is currently on "ration" until it shows in the marketplace.) Just playing some with the CFE in the cooler temps.

But to the upper assembly, I kept the buffer spring and buffer wt installed although not necessary, like Rider suggested. The bolt cycle is very small and tight, but works well you just have to get used to it. The rifle fed, shot, cycled, extracted and reloaded well, no problems. I'm using my Grendel blue-follower duramags (10 rounders).

So first impressions are very positive.

[HighDesertDrifter]

Welp, that is pretty great to hear!

[m796rider]

Shoots so nice with a can... Also using my modded Amend2 Grendel mags - Strike Industries extension gives +2.

[grayfox]

I might get there with the can also.
Last outing, last week, surprised me b/c some 120-129 loads from earlier, that were great and on-node, were shooting much faster, couldn't be the temperature b/c it was 45 deg. So a bit confused.
Does this barrel somehow shoot faster as a bolt action? I've not heard of that before, but am wondering why, what should have been 129/2360 shot 2400... 120/2450 shot 2500 ...weird.

[m796rider]

I might get there with the can also.
Last outing, last week, surprised me b/c some 120-129 loads from earlier, that were great and on-node, were shooting much faster, couldn't be the temperature b/c it was 45 deg. So a bit confused.
Does this barrel somehow shoot faster as a bolt action? I've not heard of that before, but am wondering why, what should have been 129/2360 shot 2400... 120/2450 shot 2500 ...weird.

Well, you're not tapping off any gas so that might have something to do with it...?

[Dino11]

Their is a lot of meat on the head of their bolt. You can run the 64,000 hot bolt action loads in it.

[grayfox]

I first tried out this BC-15 bolt action upper on my 18" grendel, got some surprising results as noted above. But overall the fit and function was ok.
So for this 18" grendel, the bolt action doesn't get me to any of the next higher nodes, so I've been thinking... and will try it next on a 20" 6 Arc barrel setup I have. For this one, I think I could get, maybe not to a higher node, but up "into" the existing one with 95-103 gr bullets. For the 100-103 I have been somewhere in the 2660-2680 fps, and 95, around 2780, but with the bolt action I think I could get maybe up into the 2710's and 2800 respectively. Not a real big improvement but one that might be useful. Besides it gives me an excuse to swap stuff around and fiddle in the shop a bit, you know, keep these hands from being too idle, lol.
I have a bunch of the 95-100 bullets that haven't really found a shootin' home, so maybe this time!

[HighDesertDrifter]

Hope it works out for you. Thank you for trying something new and sharing your observations.