.308 load development in my Bubba'd Ishy |
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Trappers
Groupie Joined: May 06 2021 Location: Canada Status: Offline Points: 25 |
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Posted: May 07 2021 at 7:45am |
I first posted this on another thread, but would like more discussion on the topic without highjacking Goosic's OP, which I can't wait to see that outcome!
But here is a look at my load development process in general, and where it led. DISCLAIMER. THESE ARE MY HANDLOADS, YMMV So to start things I was trying to develop some plinking rounds with some 90gr Hornady XTP'S. Previous targets showed promise, but the brass would barely hold the projectile. Needed a tighter neck, and I remember reading you could chuck your collet stem in a drill and sand it down, but I did not want to make that kind of change just to shoot a plinking round. Low and behold, the stem from 300WM (.308) fit in the 303 collet die, and now I had tighter neck sized brass for the .309 xtp. Very nice neck tension for the XTP, but now obviously for .308. On the target you can see large construction paper squares, those are my aiming points. Roughly 3"x3" squares, shot at prone, bipod, rear bag, at 50 yards. My Bubba'd ishy has a 2.5x NC Star scout scope, and I've found 3" squares are nice to zero in on with this optic at this range. So these XTP loads are 28.0gr RL-7, covered with a .223 cotton patch to hold the powder. Primed with CCI 200's, PRVI brass. They chronographed in at 2271 average. After doing some reading of another fellow doing the same in a Mosin, he stated that's around the max that bullet is meant to travel, and I totally understand and agree. I don't want stuck jackets, or bullets exploding mid air flying across my home shooting range.lol. No recoil, low noise, accurate enough, but they won't feed reliably from the magazine into the feed ramp because we'll, the SMLE was not designed short stubby pistol boolits, go figure.. I mean you could finess it into battery with enough love, rattles, shimmy and shakes, but it's not "rackable" from magazine by any means. So here comes the 180's. I have bushels of .308 projectiles from when I believed the lie that I could shoot 300WM like it was affordable I shoot from home, when the stars align. I can take a couple shots, run to my reloading room, load something different and carry on. So I started with 3 180gr Nosler Ballistic Tips over 37.0gr Varget for velocities of 2055, 2023, and 2070. Not the first group end all, but they made nice little round holes with a respected velocity IMO. The other 2 shots to finish it to 5 I did not record the velocities, I just shot to confirm the group. Now I have a decent load for 150gr .311 PRVI SP's, running 2550 out of this short barrel SMLE, so I had to try some 165's in .308 now that I knew it threw them strait enough. Next shots were with the 165's at #2 starting at 38.0gr of IMR4064. Now there is ZERO load data for what I was about to do, but I proceeded with the amount of caution and logic from my experiences handloading for other rifles, that being said I am always to new ideas, or suggestions. After comparing the brass from my zero pressure plinking development, and my 150gr PRVI SP load of 43.5gr IMR4064 (44.7MAX), and factory 180gr PowerPoint loads, I think I have a good idea of what safe brass should look like, and what a stout load feels (those 180's punish me, and the 150's with my light rifle are not pleasant from a bench either) Now I did want to see some performance from the 165 Interlock so I went up in 1.0 grain increments from 40.0 to 42.0 to look at POI shift, horizontal dispersion and brass sign. I did not chronograph these, only looking for pressure and how they hit the paper. All still printing round holes. The first 41.0g 4064 load POI looked good, compared to everything else thus far, so I tried two more shots for the 3 shot group at the top of the picture. No I was onto something, and had a "safe" range to work with. So here is where I do things differently. I am a firm believer that 10 shot groups are the real deal but that's a lot of resources, 5 shot groups tell a reliable picture, 3 shot groups look good on the internet...and 2 shot groups don't get smaller. While shooting two shot groups for load development, I look for velocity nodes where your charge weight goes up, but velocities stay relatively stable, and I know that a 4 shot sample is VERY SMALL, but interestingly enough, I had single digit SD in a .5 charge increase. Kinda neat. If this was not an SMLE, it would be fun to chase this load development further, but with another velocity node at 42.5gr, and not too much brass stress, I have a nice hunting load that is the most accurate load this 18.5" sporter has probably ever shot. So this is as far as I have gotten with this rifle and load development. I have been looking for discussions on the topic of loading .308 in the enfield. I have not fully gone through these forums with a fine toothed comb yet but this is what I have done. I read on an older reloading thread on this forum that the undersized projectiles will erode the throat and some of the chamber away. My thoughts are, if undersized projectiles are fired and they group, accurately with decent external and internal ballistics but still taking away rifle life, is it as bad as firing an inaccurate round extensively that still wears away rifle life. But let's be honest, these are 80-100 year old war horses that still work!
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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You might want to also look up Dan Newberry’s Optimal Charge Weight (OCW) method, an interesting experiment. I’ve run this test on my AR that I use for Service Rifle match shooting, it worked for me. You look for the “accuracy node” rather than a velocity node, whereby small changes in powder weight do not change the mean point of impact on the target. It really works.
I’ve not yet found a more accurate load for my No. 4 .303 rifles than 40.0 gr. Varget and 174 gr. Sierra MatchKing. It’s a fairly mild load as pressures go and will hammer the X ring in shooting CMP matches. Bullets seated to 3.05 inches and always reliable magazine feeding, which is critical for the rapid stages. I’m currently using PPU cases neck sized in Lee collet die and WLR primers. I used to play around with different bullets, powder and charge weights. I later realized that just ate up a lot of barrel life and it did not teach me anything about how to shoot. But that’s just me, we got to do what interests us and keeps is going out to the range, so experiment on! I would add that I don’t think I would put a cotton patch in the case, maybe it’s perfectly safe, but it’s going to compress under the high pressures and then extrude itself thru the neck. Maybe tissue paper? Fillers of any kind make me nervous. As does large airspace in a rifle case with medium to slow burn powders. H4895 as proven to be exceptionally versatile in reduced loads with no need for fillers. |
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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My personal favorite handloads for accuracy in the 7.62mm Enfield is the 168grn BTHP with 40.0grns of N202 and 41.5grns of IMR4064. Those barrels have a 1-10" twist rate and those particular bullets work very well for target work. I put a cutdown, 22" 2A1 Ishy barrel on a No4Mk1 reciever and the 168grn BTHP will provide you with 1.5 MOA or less. For hunting applications i use Norma 180grn Vulkan bullets with 40.0grns of N202. I recently found a No4 contoured 7.62mm barrel for a No4Mk1. That barrel is a 6 groove with a 1-10" twist. Using the above mentioned 168grn BTHP I get 1"MOA regardless. They are that accurate.
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Trappers
Groupie Joined: May 06 2021 Location: Canada Status: Offline Points: 25 |
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This is me zeroing my scout scope with this load one day. The highlighted group is at 100yards from a bipod. Then I broke my swivel stud.. and the subsequent terminator shots on the steel plate are seated from 150 yards. 9 MOA if you're curious! My goal is to off hand shoot this range, but a smaller target at 150 for hunting season. I've got a lot of practice to do
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