Bullet Weight!

[charlesb]

After putting in some time assembling a heavy-barreled .223 bolt rifle, I finally got to the point where I was ready to shoot it, see what it would do.

I had some bullets from my previous .223 left over, 68 grain match BTHP bullets loaded to a moderate velocity. There were no firm expectations, just hopes. - But I was unprepared to see it shoot all over the target at 50 yards, not really what you could call a group. Then I peeked through the spotting scope and saw the key-holing.

Back at the shop, I belatedly measured the barrel's twist rate, and found it was 1 in 12 inches. Well, that explained the key-holing with the heavy bullets!

So I ordered bullets in 40, 50 and 52 grains. When they came in, I tried a few different powders and loads for each, and a clear trend emerged... The heavier the bullet, the more accurate it was, and the less sensitive about the load. The 40 grain bullets never did shoot well with any of the loads that I tried, but the 50 and 52 grain bullets did fairly well. The 52 grain bullets did best.

I ordered some 55 grain bullets that had done well for me in the past (Hornady 55 grn V-Max) and finally found what that barrel liked. Great groups with several different powders and loads. All were one notch back from maximum, hot but not what I would think of as pushing the edge of the envelope.

My guess is that the 1 in 14 inch twist barrels must do best with the 40 grain bullets. My optimistic hopes of using the 40 grain bullets to approach 22 Hornet performance were dashed by 3" groups at 50 yards with the light charge/light bullet loads.

I am happy to report though that the 55 grain bullets did pretty well at 2,000 fps velocity. - A good thing as I have two pounds of AA5744 en route that I ordered last month. At 12 grains per load, that ought to last me for a while with those mouse loads.

In this case at least, it looks like bullet weight was more of a factor than the powder used, or the velocity I tried for.

Best results with the 55 grain V-Max in this gun came with W 748, H-4895 and Ram-Shot Exterminator. None of these three stood out as being noticeably better than the other two, at least not so far... The Exterminator powder is something new to me, it is a ball powder that is fine-grained, easy to measure and goes everywhere if you happen to spill a little bit of it.

[blue68f100]

I am happy to report though that the 55 grain bullets did pretty well at 2,000 fps velocity.

I'm assuming you meant 3000 fps here since 2k is very slow for a 223.

My 223R AR has a 1:8 twist with a Wydle chamber which means it likes the heavier bullets. Shoots one ragged hole using Varget and 69gr Gamekings. The powders I have found that has worked best for me is Varget and CFE-223. Tried H335 and 748 and they were so so, nothing to right home about. H335 is one that should work very well with the lighter bullets and give you near max speed. The load data on the H335 should be good for your lighter bullet, too. Sierra has different load data for the bolt guns vs autos in the 223R. I've been using LC brass which has a small volume when compared to most others. I think either Varget or H335 would be a good choice or powders. TAC is another one that a lot of people use and it's a ball powder. Varget is a stick powder so it does not play well with a lot of dispensers.

Keep shooting you will find a load that works and you should end up with a velocity over 3000fps. I'm averaging over 3000fps with CFE223 and a Hornady's 55gr FMJ-BT. These are the cheapest good bullet I have found. Got them from Midway for less than $0.08 apiece when they put them on sale. I bought a bulk load box of 6000 rounds last month so I have a good supply of them right now.

I'm still trying to find a load with this light 55gr bullet that my gun likes. Testing showed using Hornady Data and my LC brass I started getting pressure signs on the bolt a few tenths before published max load with CFE-223 powder. Hornady list the max a full grain lower than Sierra does.

Keep hunting you will eventually find a combo that works for your set up.

[charlesb]

The 2,000 fps figure was correct. With the 55 grain bullets, 12 grains of AA5744 gives you something around 2,000 fps. These reduced loads are from the Speer manual. They are generally accurate, and of course are very inexpensive to put together. At 100 yards for target shooting, the paper never notices the difference.

If a 22 Hornet had the proper twist for 55 grain bullets, it would push them at or around 2,000 fps. - Good for paper punching and some hunting situations. Like the Hornet, there is a low report that can be useful at times.

I am also trying for a maximum velocity load, or close to it for general use. The scope I use a Nikon P-223 4-12x40 is set up for a 55 grain bullet at 3240 fps. With that load sighted in at 100 yards, the scope's top turret has markings in 50 yard increments up to 500 yards so you can simply dial in for the range that you intend to shoot at. Getting that velocity from my 18" barrel looks like it is going to be a challenge.

Yesterday I bought a can of H335, and am interested to see how it performs for this rifle. - I've had terrible luck with Varget so far, though I know that most shooters do very well with it. I only have 1/4 pound of it left, and have yet to see a really tight group with any of the cartridges and firearms that I have tried it with. It's coming to the point where I'm wondering if I just got hold of a bad batch of it, somehow.

I use the LC brass for my mouse/target loads, and Federal brass for my attempts to creep up on 3240 fps with the 55 grain bullet from the 18" barrel.

This rifle is a joy to shoot. If it takes me a while to get the max load sorted out that will be OK... The range I use is just a couple of miles from my house. A lot of times I'll show up there just after sunrise when the wind is calm with just ten cartridges loaded. I'll shoot two five-round groups at fifty yards and then go home to document the results. When I start pushing the velocity edge, I'll start bringing the chronograph along with me.

My last heavy-barreled .223, a Savage model 25T had a 1:9" twist barrel and it liked the 68 grain Gamekings too. They will not stabilize in this 1:12" barrel though. That's a shame, as I have a good supply of them. It looks like I need to consider a bulk buy of some 55 grain bullet, maybe the Hornady V-Max. I'll be needing a plastic tip so it can serve as a pig/coyote gun at the local ranches.

[blue68f100]

I've had terrible luck with the H335. What I determine was the load was too light to get a consistent burn according to my crony results. I pushed the load into the bolt class which was about 1 gr over max for an AR. The crony number then came in and thing started improving but I was showing over pressure signs and had to stop and stick with the AR data only. I've had better luck with W748 than H335. I use the #41 primers in my loads mainly as Mag primer to set off the ball powders efficiently.

I discovered the crown on my barrel was bad and had to rework it. Looks like the tooling was dull and has some galling on the rifling right near the crown. Bad enough it had no indication of the star pattern after shooting. Only 2 of the rifling lands had the normal carbon streaks. I've cleaned it up the best I could. Since this was a cheap Anderson barrel, not worth the cost to mess with it. Surprisingly it shoots the heavy bullets good, but took a while to find the right load. Will save it for general blasting of the NATO ammo. Looking at replacing it with a heavy 24" barrel.

I have found that Varget likes to be run right at the Max to get good accurate loads and great crony number, single digits SD & ES. I'm getting 3040 fps out of my 18" 1:8 twist barrel 15' from the muzzel , ES = 7, SD = 4. W748 seams to give the same spread over a broad range.

The Hornady 55gr FMJ-BT have been the cheapest good quality bullets I have found. Midway puts these on sale on a regular basis so you can get a good price.

[charlesb]

I tried 100 of the Hornady 55gr FMJ-BT bullets, and they worked so well that I have another 500 of them coming in a couple of days. - They grouped very much like the Hornady 55 grn V-Max. I appreciate the tip about those bullets, they are perfect for the kind of shooting that I do.

In my five-shot groups, it seems like I get three or four touching each other, and one flyer that opens the group up to double the size. I've tried taking more time between shots, and I looked over the glass bedding but so far have not figured out what's up with that. Whatever it is, it seems to happen no matter what bullet and powder combination I try.

The weather here is good, but only in fits and starts due to the springtime winds here. In a month or two it should settle down considerably but in the mean-time, if I want to shoot in still air then I've got to be out there at the crack of dawn. - Brrr!

[Hakaman]

My RRA ar15 national match is 1:8 twist and it shoots 69g and 75g match bullets quite well. I even found a load for 55g bulk ammo that works well. You just have to try out different loads to find the sweet spot.

[blue68f100]

Charles,

I'm discovering that these light bullets are very pressure sensitive with the powder I'm using. Ran into a gas block problem and ended changing it out due to leakage around the adj screw. I run into the same thing but traced it back to a case volume slightly different. Ran the volume test on the rounds I tested and discovered one was slightly larger capacity. I also found that as little as 0.010" in OAL can over double the group size. Been driving me nuts trying to get the 55gr shooting like my 65 and 68 gr bullets. These lighter bullets are also more sensitive to wind too. The one thing I have learned about this Wydle chamber is it likes the OAL long, 2.240-2.260". Any thing less and it will not group at all. My next barrel will not have this chamber due to the long leads make it harder to shoot the cheap light bullets.