.375 Holland and Holland

[redneckdan]

I finally made it out to the the range to test the CZ-550 this morning. I had loaded up a few rounds of the Lee Group Buy 275gr TC that were given to me by KTW. They dropped at +.382", I sized them down to .369" in one pass....talk about grunt! I wrapped them with two wraps of tracing paper. Mic'd at .3752 after drying. I loaded them over 68gr of IMR-4064 and a magnum primer. At first I was getting 50% success on seating until I flaired the case mouths a bit more and lube the patches with some JPW, then I had no further problems with patch tearing.

The second load was a Lyman 378674 over 64gr of IMR-4064 and a magnum primer. These were also donor boolits (NOT from KTW) but the quality of the castings was sketchy at best. Again sized to .369 and wrapped twice. With this boolit I stuck with the well flaired case mouths and JPW, no tearing problems.

Both loads grouped to the same point of impact and grouped roughly 2.0" at 50yds from the sitting position. I definitely think the loads can group better. I had a light sweat shirt on and the factory recoil pad. The recoil definitely got my attention.

[redneckdan]

I picked up a double cut NEI mould here in the swapping and selling forum, .375 -304 & .375-280B. The -304 drops at about 330grs. The -280 drops at about 295grs. I sized both boolits down to .369 and wrapped with two layers of tracing velum. I loaded the -304 over 60.0gr of Tac, the -280 is loaded over 65.0gr of Tac; both loads are sparked with a winchester magnum primer. The -280 is patched a little short, the lands hit about 1/8" in front of the end of the patch, the -304 is patched just right. I'll fire the -280s just to see what happens and I'll patch the new batch another 1/4" longer.

The -280 is on the left, the -304 on the right.

[redneckdan]

Just got back from the woods. The first 3 rounds of the -304 went into just over 2" at 100yds from a rested sitting position, the 4th round opened the group up to well over 5", I'm not used to this kind of recoil...to say it was knocking me stupid would be an understatement. I used the rest of the rounds for rock snipeing at distances from 100 to 256yds (lasered), from an unsupported sitting position. I didn't miss, even at over 250yds, that rock was the size of a computer monitor. It seemed that shooting while slung up helped me to roll with the recoil.

[Bullshop]

Say Dan I have been messing with my 375 lately too. Mine is not the standard 375 but the JRS improved version.
Yesterday also shooting an NEI 320gn but GG not PP I got one of them heart be still groups. At 100 yards from rest 4 of 5 were in one hole although elongated and the 5'th was about 1/2" out of it.
I am shooting a reduced load of IMR 4350 at 50gn and the rest of the case filled with packing popcorn. Primers are WW LP standard.
I took the load up to 70gn but the ACWW alloy couldn't handle it. At 50 gn with the popcorn filler it is shooting as good as I can hold with the well aged 3x9 Leupold.
I have not yet chronoed it but am guessing somewhere between 1700 and 1800. Chronoing is a challenge right now with the daylight hours dwindling fast.
Anyway something for you to try.
BIC/BS

[redneckdan]

Sounds good to me. I'll give that a try.

Just let me know if you want me to send you some of these boolits sized at .369" for patching.

I'm thinking of trying the Lyman 375449 patched over 14.0gr of Red dot, should be good for 1300fps, pretty much duplicating .38-55 balistics.

I'm almost certain that the loads I've tried would be more than enough for anything I'd ever shoot at. Just gotta get used to medium bore rifles.

[Bullshop]

Yesterday I filled an order for some LBT 350gn LFN's. There was a wee little bit of over run so today I tried some with the same load.
The target from yesterday was still up so I just shat the same one. The result is an 8 shot group, 5 of the 320's from yesterday and 3 of the 350 from today into a nice round group that looks to be about 1 1/4" from the two widest points. God willing I will get Jr. to post it for you.
This seems to be a well balanced load for medium hard boolits from 320 to 350gn weight.
I really like how this rifle puts different weights into the same group.
Thanks for the offer on the boolits and may take you up on that later on.
BIC/BS

[Bullshop Junior]

Here is the photo that dad wanted me to post.