I've been working on a 180gr jacketed load for my M1917 and I tried both boat tails and flat based bullets. I've always read flat based perform better than boat tails at short yardage. I reloaded all the bullet the exact same way and noticed the flat based shot way left and train wreck grouping pattern at 200 yds. Boat tails performed as expected. Any idea why they would shoot so erratic? Does flat base need a slower velocity maybe?
Flat Based Bullets
- Thread starter Chief TC
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Charlie98
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What were the specific bullets?
I bought Hornady SST .480 BC for boat tails and soft points .425 BC for the flat based ones per the Hornady loading manual. Both 180 grain. Both bullets seated to .015 from the lands.
N555
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With same weight bullets and the same powder charge a boat tail bullet will generate higher chamber pressure than flat base by around 10% to 15%.
So by flip flopping between the 2 bullet styles it's as if you loaded the boat tails hotter.
For my 8mm Mauser 1gr is the difference between a nearly 1moa load and a 3 or 4 moa load. Boat tail vs flat base will have a greater effect on pressure than 1gr of powder especially in something like a x51 or x57 mauser case.
So by flip flopping between the 2 bullet styles it's as if you loaded the boat tails hotter.
For my 8mm Mauser 1gr is the difference between a nearly 1moa load and a 3 or 4 moa load. Boat tail vs flat base will have a greater effect on pressure than 1gr of powder especially in something like a x51 or x57 mauser case.
GeoDudeFlorida
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The process of load work up remains the same: whenever a major component is changed, start with the minimum lowest load recommended for the component with the lowest recommended load and work up to your best accuracy for your platform. It’s not going to work just swapping projectiles and hoping for better results.
The barrel will tell you whether flat base or boat tail bullets are more accurate. In the Model of 1917, you are far better off seating to the magazine box and not worrying about the lands. Damaged tips from recoil impact will hurt accuracy way more than jump.
Start your load work up and don’t take short cuts. Or, since you already have a satisfactory load, stick with it.
Seedy Character
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I use Sierra flat base 150 gr for my 1917, since 1975. Worked up 180 gr load in 1983, the Nosler Partition was best, loaded with 4350. Loaded to SAAMI spec, for magazine
Every rifle will have a favorite, just a matter of finding it.
Every rifle will have a favorite, just a matter of finding it.
AJC1
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Each bullet likes it's own thing. Treating them exactly the same means your favoring the results of the bullet actually worked up and hindering the other. Bearing surface alone is going to be a lot different, and the flat base will be a shorter bullet.
Lots of great responses. Thanks folks. I was treating both the same in load development because I wanted to see which one was better but I see I should have treated them separately. In my rifle, I do notice closer to the lands is more beneficial than the OALs in the loading manuals.
GeoDudeFlorida
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Try not to make too many assumptions. Even if farther off the throat is better for the bullets you’ve tried so far doesn’t mean it’s going to be better for every bullet.
Is your M1917 as-issued with the original barrel?
Winchester or Remington/Eddystone?
Thanks GeoDude. I'll give you a quick synopsis. The rifle is a WW2 rebuild but has the original Winchester Sept 1918 receiver and barrel and all is in good shape. When I first took it to shoot it mostly did a lot of vertical stringing with factory M2 ball ammo, so I had to mess with the stock and upward pressure to get everything bedded the way it preferred. Once I got that fixed, I started with Hornady 168s and they performed awesome at 100 (less than 2 MOA) but couldn't get them to group at 200 with differing loads. Then I decided to try 180s and read sometimes FB bullets perform better than BTs in M1917. The BTs at 180 with 47 grains of IMR4064 with .015 off the lands have performed very well. As indicated in this thread, I just duplicated the BT load with the FBs. I'll heed all the advice and start over with the FB load development. Thanks again,
GeoDudeFlorida
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Sounds like a good rifle.
I’ve shot pounds of Sierra 180gr BTHP in a couple of Remington and Winchester M1917’s with 38.5gr of IMR 4895 but I always seated to the tangent (the point where the shank slopes into the ogive) which is about where Sierra recommends. The only surplus rifles I had/have that shoot better with flat base are Enfield No.1 and No.4 rifles. The Enfield rifling seems to be made for them.
I'd like to try SMK bullets but been finding the Hornadys at good prices, so haven't tried Sierra bullets yet.
AJC1
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There are a few good bullets worth testing. Berger, sierra, and lapua all make great bullets. Your shooting Hornaday already so I didn't add them to the list.... berger has some interesting shapes like the hybrid that may work well for you.
GeoDudeFlorida
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I haven’t tried the Hornady but have heard good things. I’m thinking you might not get better results with a flat base in the Winchester barrel but if you do it will be probably be with a slightly faster powder and a lower charge. The base has to be seated pretty deep in the neck. I never worried about trying to crowd the lands. It just seems to depend on the barrel though.
Varminterror
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This is kinda like saying “vehicles with big engines can drive faster,” then going out and buying a Peterbilt semi-tractor instead of a Corvette.
Short range benchrest has traditionally been dominated by flat base bullets because they offer long bearing surface, clean gas seal, high stability to initial pressure front, and great balance between center of gravity relative to center of pressure. But short range benchrest isn’t dominated by Hornady soft points and M1917’s.
Personally, I would have revisited why the rifle grouped “well,” (relatively speaking, I guess, in this instance) at 100yrds but did not group well at 200. That’s a huge red flag for me.
.45Coltguy
Member
In my three 30-06's, 03A3[totally sporterized], Ruger MK II and Ruger No.1B, I have had very good luck/accuracy with Hornady Interlock FB bullets. Whether 165 or 180gr using either H4350 or Ramshot Hunter. For whatever reason, never did try any boattail bullets. Just stayed with what worked well from the start.
Side note: Had very good accuracy with Hornady 150gr FB Interlock's using IMR4064, but, moved up to 165-180's later on. That has been my jouney with the 30-06.
Side note: Had very good accuracy with Hornady 150gr FB Interlock's using IMR4064, but, moved up to 165-180's later on. That has been my jouney with the 30-06.
If your M1917 has the original military barrel, that is probably why you are having issues. None of my M1917's have new barrels, one has seen a lot of use. The M1917 was relegated to training in WW2, given to Allies, (the one with the most worn barrel went to Canada during WW2) and very few were not used. And, these barrels are war babies. It was OK to start out with cutting tool that made a large bore, and use the cutting tool up, till the tool had to be replaced. During a major war the most important thing is getting the product out the door.
Worn barrels do strange things, barrels in general will do strange things.
this rifle shot boat tailed SMK's well
Flat based core lokt's were acceptable
This barrel
Really likes SMK bullets
did well with flat based Hornady's
really did not like Core Lokt's
No idea why one barrel did acceptably and the other puked the same bullet.
Something about flat based bullets, don't expect them to stay supersconic long. At some distance, downrange, they will tumble.
OK at 300 yards
tumbling at 600 yards
Even boat tail bullets will tumble, and this was a real surprise. Never expected such a well characterized target bullet to tumble, but it did
shot well at 300 yards
tumbling, tumbling, at 600 yards. The actual string velocities are on the targets. I was able to set up a chronograph that day.
If your barrel does not like the bullet, you just have to stick to the bullets that work. Why one bullet does better than any other, my guesses are as good as anyone else's.
These shot well in the same rifle in which the 190's tumbled. And they were slower than the 190's. Guess I will use them instead
Attachments
nettlle
Contributing Member
Whatever bullet gives me the best groups. Whether it be flat based or boat tail. Been a Sierra fan since 1965 and am getting good results with these HPBT in my 308. Read good things about Berger but have not tried them yet. FedEx dropped these off today.
AJC1
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I got one of those marked 175. As Paul harrel would say they are my previous.
GeoDudeFlorida
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A 180gr Match King at 2500fps won’t let you down.
AJC1
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Standing by for your best load and as expected I'll bracket it
GeoDudeFlorida
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Well, that’s probably 48.0gr of IMR 4064 in .30-06Spg. I like that load in my Eddy’s’17. Does pretty well in the 721, too. Not so much for the Model 30 Express. It only likes flat base bullets.
AJC1
Member
So 42 ish in 308 and make it count.....
