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Topic: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel. (Read 402 times) previous topic - next topic

Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

I measured the chamber on my Proof Research Carbon wrapped barrel and got an overall chamber dimension of 2.880”, so 20 thou off the lands and I get a COAL of 2.860”.  Or 2.167” from the base to ogive.  The final rounds were + - .001 base to ogive.  The rounds only fit in my steel M1A mags, they were .075” too long for the MAGPUL 7.62x51 mags.

As to the charge, after a bit of research I decided to start at 42 Grains of H4350, and increment up to 42.6 in .1 Gr increments.  Muzzle velocity is estimated at around 2750.  Exact velocity will have to wait until the next trip to Quantico in two weeks.  Unless I get a LabRadar unit… 

At this point I’m more interested in groups and pressure signs than I am in velocity.  At estimated muzzle velocity of 2750 I should have a velocity of around 1122 FPS at 1600 yards with this load.

With the Federal match Small Rifle primers I get about half the cases with a small ragged ridge around the impact point of the firing pin.  The primers them selves are not flattened out excessively.  I’m also scrapping the Federal Match primers as I’m getting 1 failure out of 30.  If I can’t trust them to go “Boom” I can’t trust - or use them.

Charges were dispersed with an RCBS Chargemaster and verified with a beam scale, adjusting by adding one or two pellets to get the same weight in each of the three round test groups.  The individual Chargemaster charges are + - .05 Gr in accuracy.  Each was individually adjusted.  This process with the 123 Gr ELDM rounds yielded 2805FPS + - about 3 FPS according to the LabRadar unit I borrowed.

Results Charge VS Group
42.0   .425”
42.1   .237”
42.2  .650”
42.3   .518”
42.4   .702”
42.5   .942”
42.6   .578”

Velocity later on…

Bryan

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #1
I wrote up a page long response to this, but I think I'll cut it short and say:

You REALLY need a chrono. Buy one while you can still see your credit card, please.

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #2
Alot of us run in the 42+ range. But I think it safe to say none of us started there. That's asking for trouble in my opinion. Stay safe...read your manuals...and start low and work your way up..it only takes a hand full of rounds to find your max charge wieght...
Grant

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #3
So "after a bit of research" you STARTED 1.7 grains over Hornady max. load and .2 over Hodgdon max load? Then proceeded to go .8 to 2.3 grains over book max?

Just because it worked in a lot of rifles on the Internet doesn't mean it will work for yours. There's probably 2 maybe 3 good loads below where you started.

Several threads on this forum alone where people couldn't shoot 140-142s without hitting pressure. What exactly is the point of chasing speed without a chronograph?

A lot of shooters like to run a mild load through their brass the first 1 or 2 firings and find a mild to moderate node and find a good seating depth.

If I'm coming off too harsh I apologize but you're flirting with disaster and probably trashing your brass as well!

Dave

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #4
I wrote up a page long response to this, but I think I'll cut it short and say:

You REALLY need a chrono. Buy one while you can still see your credit card, please.

Manual first then chrono
Dave

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #5
As mentioned get a chrono. Doesn't have to be a $500+ lab radar. Get a Magnetospeed sporter for around $180. Accurate and easy to use. Will give you a good velocity and let you know your ES/SD numbers.

Also as mentioned starting at 42grns is not advisable. I started at 40.5grns and worked up to 43 at the same 2.860" although it is .030" off in my rifle. You should have started lower but if it seems safe in the rifle than you can play with the charges and see what works.

And get some AICS style mags. They will hold the rounds at that length.

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #6
I wrote up a page long response to this, but I think I'll cut it short and say:

You REALLY need a chrono. Buy one while you can still see your credit card, please.

Yes. I should have replaced chrono with reloading manual

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #7
Plenty of places online to get data like Hodgdon and Hornady sites but no way without a chrono to get accurate velocity and ES/SD so I would say get a chrono first.

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #8
I assumed he found some data somewhere, but we all know what assuming does.

I want pics of the brass!

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #9
Thought that might get a few interesting comments.

Maximum load for “starters” is a function of what manual you grab.  For the Hornady 140 Gr ELD-M.  Granted all the bullets listed are different profiles. 

Hornady  X          41.5
Berger   1St         40.7
Speer    #14         No data (Online no data)
Barnes   4             No Data (Online 40.1)
Lyman    49          No Data (Online $35 for that answer)
Nosler   8              41.0
Sierra                    42.0
Hodgen                40.0 C

After that it’s what the cases tell you.  And yes I have all these books…

Are the loads a little hot, yes, but only because I was not getting what I wanted out of the lower loads tested in previous outings.  So no, I did not throw caution to the wind an yell “yeah ha”.

For those that are all shocked and shaken over my loads, look at “Berger 140 Vld Loads “ on this forum.  One of those loads applauded by all is 2.8 Gr over the max listed by Berger for a 140 Gr bullet at H4350 40.7 Gr @2634.  His load was H4350 43.5 Gr @ 2875.  And no one pointed out that he was way over the high end and 241 FPS on the fast side.

Nary a comment.  In fact most of the loads listed for “Berger 140 Vld Loads” are almost all over the max listed by the manufacture for that bullet.

As to my loads and the 147 ELD-M, Sierra lists 42.1 of H4350 for their 150 GR HPBT.  So no I’m not actually way on the outside for a bullet of that weight.  But Sierra bullets just don’t perform well in my barrel…  My M24, that’s another story…
Each barrel and bullet combinations are going to yield different results than the others.  That’s because metallurgically they are all different.  The person who proclaims a specific load/bullet combination for all likely does not know what he’s talking about, or can’t comprehend the combinations.

When I flew for UH-1V’s with Lifesaver at Ft Hood we had more sheet metal work on our birds than any other unit stationed there.  That’s because on range pickups we routinely pushed them to 120 Kts, AKA VNE, Velocity Never Exceed, and on occasions a tad faster.  Hospital transfers were at a sedate 90 Kts.  In Iraq I flew CH-47’s, as fast as I could get them to move, generally around 145 - 150 Kts @ 50,000 Lb.

Am I going to shoot all my ammo at the hot end, no.  Am I going to shoot some of it at the hot end, yes.
Your mileage will vary form mine.

As to the brass, take a look...

- Brayn

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #10
bw we kinda try to look out for each other on here … their was no mention of lower loads tested in your first post... you said after a bit of research you started at 42 gr... so that's kinda confusing … to those of us that replied it sounded like that's where you started and that's pretty risky in my eyes... as im sure it is to the others on here that said something... but hey its your face behind the bolt... start where ever ya like...
Grant

 

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #11
Your post said and led me to believe you STARTED there. Unless I missed something nothing was said about your previous lighter loads.
Dave

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #12
OP writes:  "As to the charge, after a bit of research I decided to start at 42 Grains of H4350, and increment up to 42.6 in .1 Gr increments"  

Pretty easy to see why some here would have thought you started high.

Anyway, I own an RPR, how do you like the barrel?   And is your combination grouping?  TIA, lg

Re: Hornady 147 Gr ELDM, RPR w 24”Proof Research carbon barrel.

Reply #13
W/O pressure transducers measuring case heads or looking at primers is useful but not an absolute answer.

A Chronograph is a cheap insurance policy ---- less than a junk Chinese scope.

MY rule of thumb is: IF the tested velocity is higher than any pressure tested velocity data, with the same bullet, components and barrel length, I'll dial it back.

As we know, muzzle velocity is not the answer ----- retained velocity, reduced wind drift and accuracy are.

If I want to push a 6.5 pill very fast, I uncase my Ruger No. 1 in 6.5 Bee. (No where near as much fun to shoot as my suppressed Tikka 6.5 CM !)