Oh I just wanted to see what it looked like using the drop tube. That's is VV's max book.
I'll work my way up from known safe and see where it goes
N140 fps 20" 75-77gr
- Thread starter 95GTSpeedDemon
- Start date
I'll work my way up from known safe and see where it goes
kyotekiller25
Silver $$ Contributor
No, I don't know what it is with these long pointy 22 cal bullets, but I'm still getting around .008" variance in seating depths with a Forster micrometer seater. It's very annoying. I have to seat then all .010" long, and gradually go down to where I want with each one after that. It's a slow process...
Only for the 77gn TMK - a max load I find incomprehensible on both pressure and room in the case grounds especially at the claimed tested 2.26-inch COAL in what should be a short-freebore industry compliant barrel/chamber. Other 77s are given max charges of 24.2, 24.5, and 25.0(C) gn depending on bullet make.
The 80gn SMK data gives a maximum charge of 23.0gn N140 despite this being tested in a barrel with a freebore allowing this bullet to be loaded at 2.559" and tested at 2.551". ie as per the chambering used on many XTC rifles and with a longer freebore chamber than your Wylde. This is a very old load that has been in Viht's data for many, many years and is low despite Viht using Lapua brass. (Actually, it is so old that it may have been tested with the original Lapua brass that had the lowest capacity of any commercial 223 case on the market. Many years ago, Lapua moved to a much higher-capacity version marketed as '223 Match' which allows at least an extra grain of N140 with these bullet weights.)
I would dispute opinions that current N140 is much faster burning than older batches, and say that as one who has used this powder in a number of cartridges since the early 1980s, many years before it was first imported into the US. Yes, QuickLOAD has changed its burn rate value, but it has done so for many Viht powders based on user feedback. Do NOT believe burn rate charts (or QL's default burn rate values) for many powders in the range. The company serially showed (and for many still shows) its powders as being much slower burning than they turn out to be in practice.
Here's what I found a couple of years back as part of a series of range tests for H4895 and VarGet alternatives in a longer throat length and 30-inch barrel F-Class 223 rifle. My allowable max charges are c. 0.8gn higher than in a true SAAMI chamber because of the additional freebore. Your Wylde chamber will be somewhere in between the two. A standard (and essential) part of the kit using most such powders in 223, even with the longer COALs that the chamber allows is a longer drop tube, in my case the Forster funnel with a small-bore 5.25-inch tube.
https://www.targetshooter.co.uk/?p=3856
See also the final section of
https://www.targetshooter.co.uk/?p=3934
for my look at N135 and note how far out both QuickLOAD and burn rate charts are for it.
75gr EDLM had a 26.2 max charge, but were just splitting hairs.
ill check those two links out too.
im not opposed to loading long if the barrel likes it and i can get the speed im after.
i emailed berger about their load data being so much lower. its figured with nato pressure. they said they are going to update the next manual (im assuming with .223 rem data). they said its conservative (knew that).
capstone owns VV also lol
capstone owns VV also lol
That risks falling into the trap of assuming bullets of same/similar weights will always have same/similar maximum charges - often not the case.
Although weight (inertia) is the primary factor in determining pressures and hence maximum charges, there are others which can and often do, affect outcomes. The 75gn ELD-M has a 40 thou' shorter bearing surface length than the 77gn Sierra MK, so all other things being the same, it will generate lower pressures. Another important factor is jacket thickness / hardness and Hornady match bullets have a history of being thinner / softer than other makes resulting in some shooters using them as varmint or game bullets as they expand rapidly and thanks to the acetyl tip being driven back into the jacket explosively. I've no experience of the ELD-M, but its same weight A-Max predecessor was well known as a highly frangible bullet which didn't just expand rapidly in tissue, but had a near explosive effect, and in the UK and Europe was a popular model for shooting red foxes with the 223. Users were also able to work up to very high charges and quite startling MVs without producing pressure symptoms as a result of these characteristics.
I discovered the reverse of this effect the hard way years ago when I pulled the 173gn FMJBT bullets from some ancient (1920s) .30-06 M1 rounds I acquired and loaded them up in a 30-06 sporting rifle with charges that produced moderate pressures with the 175gn SMK. The first round fired comprehensively blew the primer, so I had to pull the lot for a second time. In those days, we had the benefit of the late, great 30-06 guru German Salazar on the Accurate Shooter forum whom I contacted on this outcome. The response was one of complete non-surprise, the old US military bullet being notorious for generating excessive pressures and needing loading with much lower charges than apparently similar models, exceptionally hard jackets being one cause.
Yes. They arent apples to apples.
Infact, with the same 24.1 charge, the 75 eldm was about 30fps slower than the tmk and 75 berger at the same COAL. I actually looked at a few bullet n140 loads to see if there was any that I had on hand that modeled the TMK closely so that I could do pressure testing without wasting my tmks. It didn't appear so
Infact, with the same 24.1 charge, the 75 eldm was about 30fps slower than the tmk and 75 berger at the same COAL. I actually looked at a few bullet n140 loads to see if there was any that I had on hand that modeled the TMK closely so that I could do pressure testing without wasting my tmks. It didn't appear so
I had a pretty load for 90gr Sierras in my AR with N140. When I thought about trying some of the Bergers that I have, I looked at the bearing surface (which was significantly shorter) and concluded that there should be less pressure.
Not even remotely safe. They shot incredibly well, but about six or seven had the primers fall right out. Only clue I had there was an issue was a dead trigger. One of the primers made its way under the tail of the trigger and locked it up.
I decided to drop the load even for the Sierras after that experience.
What primer?
Wow, i thought those would be softer and show pressure signs before just falling out.
dhagerty40
Gold $$ Contributor
He actually stretched the primer pockets from over pressure.
Doing that to the brass likely requires more pressure than flattening/cratering a primer right?
dhagerty40
Gold $$ Contributor
Yep!
I just looked up some of my old info and it wasn't N140, it was AR-COMP. That being said, I think the Sierras can take about 3/4 of a grain more powder than the Bergers. Not sure what the reason for that is though, as the bearing surface is shorter (these were VLDs). These were out of a Bartlein GainTwist.
Belly Benchrester
Silver $$ Contributor
What size drop tube? I have a 8” tube and still crunching powder
It's around that in length, and about .175 diameter. There is still crunching taking place. I think the big difference is I'm seating to a longer overall length than most people with ARs are
Who's barrel and how many rounds through it?
Saturn and less than 100
I never worried about crunching powder while seating the bullet. It will help prevent the bullet from getting pushed back. Turn the radio up.
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