20 caliber Grendel

[msalm]

So I finally got the metalwork done and bolted in a factory stock. Howa mini, 23 1/2” Mullerworks 4 groove 11 twist. About a #4 contour i fluted heavily w/ 6 flutes so it’s relatively light. Not too much over the factory 22” barrels. I have another B$C sporter on the way as I tried one with my 22 Grendel and it’s really a nice stock.

Bullet of choice and the only one I want to use is the 40gr BIB’s that I have 500 of. Started with new old stock Lapua Grendel sized down in Hornady 6mm and 22 ppc dies, then final size in a Redding 20 ppc FL bushing die. For fireforming it took 31gr Norma 203b (r15) to get a fully formed case. 29gr and lower had soot on neck and shoulders and didn’t iron out a thing.

After getting a decent fired case I weighed with and without water and came up with 35.2gr of water capacity.

Sooo, given this information, any ideas of an ideal powder and charge weights to look at? Goal is an all-around coyote killing machine with best point blank trajectory possible...barrel life doesn’t matter in the slightest but with the Howa mini I don’t think 63,000+ loads are prudent either.

[PGW Steve]

I ran your case volume in QL and since I'm a big fan of Hodgdon Extremes, I'd pick H4895. It doesn't list that bullet, but a 40gr Berger and 28.1 grains is 3622fps and 55K pressure....Doesn't look that exciting compared to a .204, but with that case capacity, this data is probably well conservative. Use with caution.

[Gary in Illinois]

I have found that for heavier-bullet loads in my 20 Titan, IMR 8208 and Benchmark perform very similarly: good velocity and excellent accuracy. I have used 26.0 - 26.8 grains of either powder with 55 grain Bergers. Accuracy has ranged from .068” to a high of .441” for three shot (I AM concerned with barrel life ) groups at 100 yards. I don’t have velocity readings handy right now but these loads are approaching the top in my rifle.

Please be aware that these loads are shot in my very sturdy Bat rifle with extremely tight tolerances; they are likely not suitable for production rifles. My CZ 527 in the same chambering begins to show stiff bolt lift at 25.0 grains so start low and work up slowly with close attention to pressure signs!

In my opinion, this is an excellent cartridge for what you have in mind. Repeating myself but start lower and work up very cautiously.

[SmokinJoe]

My 1st thought when reading your post is that you got a really good barrel to work with. I have a few of those and they all shoot extremely well. For your cartridge, and my experiences with 20-223AI, I think the recommended powders are right where you want to be. I would add the 39 Sierra, 40 Berger and 40 BT to the bullet mix. I'm not a coyote hunter, just shoot paper and PD's so bullet preference is probably different. Randy makes great bullets, I ought to know. IMO, your 20 Grendel should be capable of the 4,000 fps zone with 40 class bullets.

[L461]

I cannot find my data on the 20 BR I built a few years back but I use 28grains of 8208 behind a 40 Vmax in my 20 PPC this gives me a neat 4000Fps

Can I suggest you start there and slowly work up.I will be very interested in your results as this is my next "To Do" cartridge