Long Range Pistol Project "30 BTAC"

[Fiftydriver]

Impressive looking handgun for sure, BIG!!!

Just wondering, how would it compare to a 300 Dakota or 300 Lapua which can easily be chambered in a plain old XP-100 or similiar receiver?

Just seems like a hell of alot of work to go through to get the same case capacity as the Dakota. Plus, from looking at your receiver, you could easily fit Lapua length wildcats into that big girl easily. Why not get all the performance you can if your going to go with a receiver that large?

Just curious how how the numbers compare head to head with the Dakota or 300-338 Lapua. Just doesn't seem that the 408 case would handle enough pressure to make it outrun the Lapua or even match it.

When you get more numbers let us know how she runs. Very interesting.

 

[Black Diamond 408]

Kirby,
So far i have been loading the same 5 cases, got 7 loadings on them so far. This short fat case seems to be stronger than any brass ive seen. I have not found any load that will pressure the case, im almost out of room with H1000 and round primers after firing. Pockets are just as tight when i started. When you shorten a case that much the whole case, except for the neck, is much thicker than standard brass. With the large case head and short length of the case it seems to produce less pressure. A friend of mine has a 300 Dakota and he is using 85 of H1000 for a top load, 210gn bullets.

I started out to build a 300 Lapua, but what is the fun with that? I wanted somthing different that no one has. I'ts a lot of work to get the brass made but thats part of the fun. Once the brass is made it looks like you will get a LOT of reloadings from it. The goal was to have a 30cal.
long range pistol shooting heavy high bc bullets over 2700fps. From the early results 2800 will be no problem at all. If you compare a Lapua case to a cheytac case, but make them both the same capacity as the Lapua, the cheytac case will be heavier built. Everyone knows that a short fat case has less bolt thrust pressures. Powder ignition is more consistant, ES spreads are running 4-6 for the fired cases, forming cases they are running in the 20's

Once i get some of the 180 and 210gn HATs i will have more data to post. I'm assuming the
8 twist is too fast for the test bullets i have been using. I might get a 10 twist barrel for it so i can use some other bullets as well.

This is just a new toy for my box.

 

[Fiftydriver]

How does shortening the case strengthen the case head? I do not understand that. Also, how does it thicken the case wall just ahead of the solid case head?

I was just mentioning the performance because you listed in your post that the 300 Dakota would produce performance above what your seeing right now. In fact I have seen some 300 Dakotas get +2800 fps with same bullet weights as your using but doing so in a 15" to 17" barrel length, not 20".

I have never been a real believer that if you had two different case designs with the same case capacity, that the shorter fatter case would produce noticably higher velocity levels or offer dramatically better velocity spreads. I have seen test over test from wildcat designers that said their short fat cases far out performed the longer case designs with same capacity. That generally held true until customers actually started reporting on the wildcats andd it has proven to be more hype then anything else. Perhaps velocity is more consistant but from what I have seen, it is not by enough to really make it worthwhile in most cases.

Now for really small BR cases, perhaps, I do not deal with that type of chamberings much but for large capacity magnums, I have never seen any real advantage.

Again, if your design and the 300 Dakota will get the exact same velocity levels, just wonder what a 300-338 Lapua could get in a handgun, maybe I will just have to make up a 300 AX in a handgun and see how she does.

Keep us posted with your results. I am certainly with you on the something new idea, hell, thats how we get most of our new fun toys. I have been working on a semi-auto wildcat in my spare time for use as a coyote calling huntng handgun. In a standard 4.5" semi-auto handgun, I am seeing 1700 fps with a 125 gr 357 bullet and with 15 round mag capacity so I totally understand the something different thing and I also agree, its alot of fun.

 

[Black Diamond 408]

A while back i disected several of the magnum cases to see what the web thickness was. This is when i was having some issues with the 408 brass and the 338 wildcats. As you know the cases only take so much before the pockets go. I was testing cases for cheytac to see what could be done to strengthen the case. There is a big difference between a RUM case, Lapua and a Cheytac. The lapua had more web than the RUM, the Cheytac had more than the Lapua.
I talked with a engineer from Winchester Brass, he said that the longer you make the case the
more pressure will build up. He said the WSM case has less pressure on the base vs a 300 win mag case. The larger the base the less pressure will develope, as long as you have the same
powder capacity. The Lapua is a shorter case and much less capacity vs a 408-338 case. If you had a Lapua case the same length as a 408 case the pressure would be extremely higher and the case is more narrrow, more web area pressure. Most of my findings are based on what the
guy from Winchester explained to me.
I was in the small BR game years ago and the short fat cases were winning all the matches, magnum calibers may not react the same way for accuracy, testing will only tell. Heavy recoiling guns are not as accurate as a 6mm PPC, but a 6ppc will not get to 2000yds. I fired many groups with my PPC that were almost imposible to measure, 5 shots looked like one bullet hole. .006 was my smallest. But that is a whole different ball game.

 

[Black Diamond 408]

I finally got some time to do some real load work for the pistol project. I found a good load
using the 220gn SMK bullet, 85gns of H1000 powder, 2800fps. Here is a pic of my last test group. 535yds, 1.75" The wind was gusty from the left, i held point of aim on the lower left corner of the steel plate.

I will try and tweek the load a bit more to see how the results change.

 

[sewwhat89]

Any updates?

 

[Ernie]

Dave made a trip to Gillette and we spent several days working at pd's from 1,900-2,000+ yards. The third day, which was half of a day, the wind was so bad, but we had fun shooting anyway. Loads had been developed for the 210 & 220 SMK's, so those were the bullets we used. The barrel is an 1-8 twist but it was not throated for the higher BC HAT's. I will say that on four occasions we got so close that we thought we had a kill, only to realize after driving down there that it was a miss. Once we start using the higher BC bullets I believe our success will be quicker. We saw our own impacts about 97% of the time through the 8-32 NXS, when shooting. So, the brake and everything worked great as well.

 

[Black Diamond 408]

Hey all,
Yes i got to meet Ernie and he showed me a real good time, learned a few new things along the way. I found it totally amazing that we could spot the shots through the pistol scope along with the spotting scope. At 1900+ yards the bullet travel was 3.3 seconds. One of our closest misses, maybe a 1/2" or so, was at 2150 yards. The bullet strike was through the top of the mound just under where the dog was sitting. Close inspection of the mounds you could see the bullet strikes very easy, we dug out a 210smk bullet and it was perfectly intact.
I would recomend the SERB Rest, made it real easy to get back onto the Pdog after recoil.

The First day was overcast and periods of sprinkles, the dogs didnt seem to like this to well. By late afternoon the sun started to come out and so did the dogs. Then ofcourse the unthinkable happened, my trigger assembly started to malfuntion. I found the body of the trigger case was made from a mild steel and the cocking piece was wearing a burr when cocking it. So that ended our day of shooting. We went back to Ernies reloading shop and found a 2 ounce trigger he had laying around. I installed and adjusted the trigger to what might be 1 ounce or less. We loaded up the empties and set our sights on a early start as high wind was predicted for Saturday. Sure enough sat morn the wind was allready up when we got to the dog town. We
brought a large steel plate along to see what kind of group we were getting at these distances.
There was a Highline running across the range where we were shooting, the Swaro showed 1920yds from the base of the pole to my truck where we were shooting from. I brought my ATV along for quick rides out to the target area. By the time Ernie got the rest set up and i tool the plate out to the highline poles, the wind was allready 20mph crossing. Sun was out and so was the dogs, but with that wind it looked like the day prolly was going to be a bust. After the pistol was disasembled the night before we decided on a few sighters to see just where we was at. Just a note on the pistol set up: 8-32x56 nightforce, NP-R1 ret. 40moa base. At these distances all of the vertical adjustment was used in the dial ups, and half of the retical in the scope. Windage proved to be the real problem on the second day, all of the adjustment was used up in the scope and we had to use the hash marks in the retical for the rest. The biggest problem was remembering what mark we were using as the wind was gusting and we were shooting over several valleys. The new trigger performed perfectly and soon we were sending lead down range. Ernie fired about 10 shots at the steel plate, i recorded several hits in the spotting scope. We drove out to the target to have a look see, there was at least 3 hits on the plate and the wood pole had 5 bullet strikes just above the plate. We estimated the group to be around 18" at 1920yds in the gusty wind. Around noon we decided to call it a day as the wind was increasing. All in all it was a great trip, i look forward to doing it again next year with my updated rig.

Ernie and I went over on how the pistol operated and any changes that should be made to make it perform better.

1. Make a bag bar on the bottom of the pistol grip so it will track even better.
2. Machine a new picatinny rail scope base that has more MOA built in. I am
going to build up an ajustable base that has 30, 40, 50 and 60 moa possible.
3. Re throat the barrel for the 210 HAT bullets

Thanks to Ernie and his Wife for their hospitality

Dave