6.5 creedmoor LRP high pressure

I bought a LRP in 6.5 creedmoor about a year ago and have approximately 300 rounds through it. I have been shooting H4350 with pretty good results but on the high end of the powder charge of 42.1 grains with a 143 ELDX hornady bullet at ~2800fps. I load the round with a .002” jump at a 2.880” COL. Most of the shooting was in the cool months in the 40-50f temp range. I have seen high pressure signs all along, stiff bolt, flat primers, loose primers., etc... I have started backing the load down due to high pressure signs and loose primer pockets with Hornady brass. I am currently at 41.1 grains but am still experiencing high pressure signs , stiff bolt and loose primer pockets with once fired hornady brass strangely getting the same 2800fps. I thought maybe I have carbon in the free ore area so I looked at it with bore scope and it’s not evident.... maybe because I don’t have trained eye??? I rechecked my bullet seating depth with a sharpie and don’t see any change. I thought H4350 was pretty temp insensitive??? I’m not sure what my problem is and am hoping to get some help from you guys. I am soaking the throat with Kroil and going to try scrubbing clean to see if this makes a difference.

My recommendation would be to get some good brass - meaning Lapua. I've had more headaches with various cartridges when using Hornady brass than I'd care to recollect.

Might give Reloader 16 and some other powders a try also.

I have a 12 LRP 6.5mm Creedmoor that would show high pressure signs with factory ammo, and hand loads at 57,000 psi, 47,000 psi and 37,000 psi.
Primer pockets were completely worn out after 4 reloads.
It shot incredibly accurately but it sure was hard on brass and primers.
I carefully recorded the results, took pictures of the brass with flattened primers and of the primers after they were deprimed along with the loads.
The key issue for Savage was the factory ammo that was flattened enough that you could see the head stamps were flattened.

After talking with them and sending them the pictures, they had me send back the rifle and bored out the chamber a few thousandths.
I have actually gotten 25 reloads with Lapua brass and small rifle primers. That could have never happened with the initial factory bored chamber.
That solved the problem. Even better, it shot just as accurately as ever. I now shoot 57,000 psi loads with the primers still rounded.

I now have over 4,000 rounds through the LRP and it still shoots as accurately as it did when it was new.

I think you and I both got chambers bored out with worn reamers.

Thanks fellows for the replies.... I guess it’s going to be a tough one to figure out. I think I may call Savage and see what they have to say. I have been cleaning the throat and barrel for about 3 hours this evening with some Kroil and don’t seem to be able to get it completely clean. I’m going to take it to work tomorrow snd look at it with bore scope again and see if I see a difference. Any suggestions for something that works on carbon better than Kroil?

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.002” jump at a 2.880” COL.

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Changing the COL to 2.800" (Hodgdon data) may solve the problem. This would be like adding freebore. Seating the bullet shank deeper into the case does not increase pressure. Test have shown it will lower pressure.

SAAMI maximum COL is 2.825"

Hodgdon max is 41.8 grs, so i would say your running at maximum pressures now. Case life will be about 3 firings. http://www.hodgdonreloading.com/

Many reloaders think getting close to the rifling is a good thing, not always, unless the chamber is cut to the bullets specifications. Many factory rifles will shoot great with bullet jump.

QuickLOAD indicates that seating the bullet deeper into the case by 0.010 would increase the pressure by about 350 psi.
That is only a half of 1% percent and not a significant difference even at higher psi levels, especially when powder lots can vary + or minus 3%.

I haven't seen a significant variation in results with a 0.010 change in seating depth.

That amount to about 5 fps in muzzle velocity.

That magnitude of change is within the combination of variations that occur in each round when reloading.
That is why even the best reloads when shot measured by a chronograph show a SD of 4 to 7 and factory loads show SDs of around 15.

QuickLOAD also shows that the 2.810 O.A.L. at 42.1 grains of H3450 powder would create 58,277 psi.
The OP's reduced load of 41.1 would create 51,703 psi.
The OP shouldn't be seeing high pressure signs at 51,703 psi range unless he had the 143 ELD-X jammed into the rifling and his data says he doesn't.
I will admit that he is very close to doing that, and reloading variations could easily cause some of his loads to seat into the rifling.
Seating into the rifling causes a severe pressure spike that could easily create the symptoms the OP reports.
I would recommend he seat his loads back closer to 0.020.
I have found that to be the most accurate jump (=/- 0.005) for most of my loads, including the Hornady bullets.

I had recently saw signs of high pressure with my Savage 12 FV 6.5mm Creedmoor at 58,000 psi level using IMR4166 powder, but not did not see similar high pressure signs when using IMR4451 or IMR4350 powder at similar pressures.
The signs with the IMR4166 were significant enough, similar to the symptoms reported by the OP, to cause me to unload about 96 rounds loaded with IMR4166.
A hot lot of IMR4166 powder could easily have caused that situation.

By the way, if the lot of H4350 powder the OP is using is at the upper limit of energy by 3%, it could easily increase the Pmax close to the 63,091 psi Pmax for the 6.5mm Creedmoor with the 143 ELD-X.
The range of 3% is a quality check range, but QuickLOAD indicates that some powders can fluctuate by as much as 10% and provides warnings for a 10% hot or cold powder with each set of data.

In my reloading for 3 different 6.5mm Creedmoor Savage rifles, I have found that the Hornady 143 grain ELD-X and 140 and 147 grain ELD-M all show high pressure signs slightly at the same pressure level before any other bullet from the different manufactures with which I reload (Sierra, Nosler, or Berger).
I can't explain that because I am loading them all 0.020 short of the rifling.
That tendency of the 143 ELD-X, coupled with a powder lot on the high energy side, could easily tip the scale with a hot load over Pmax.

As I have indicated in post#4, there are also other reasons, like a tight chamber, that would cause the pressure rise and cause high pressure signs.
In my case, it was very clear it was the chamber when I was getting high pressure signs at load level that was well below the pressure of the minimum load on the Hodgdon table.
The OPs problem could be a combination of a slightly tight chamber and pushing the loads too close to Pmax and the rifling with a high energy lot of H4350 powder.

I would suggest he try another powder or move the seating depth back from the rifling a bit to see if the high pressure indications also appear at 58,000 psi.

Quote:

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WARNING: QuickLOAD is a computer simulation of centerfire cartridge performance. YOU MUST NEVER just “plug in the numbers” and use QuickLOAD’s output for a load recipe. That is foolish and dangerous. There are many reasons why the data QuickLOAD generates may not be safe in YOUR gun. Before loading live ammunition, you should always check with the powder-makers’ most recent load data. In fact, you should check multiple sources if possible, and consult with individuals who actually load for that cartridge. Sierra Bullets offers free load maps which, in general, are fairly conservative. Even when using manufacturers’ load data, start 10% low and work up. Differences in brass, primer brand, and seating depth can make huge differences in pressure. Always reload conservatively and always double- and triple-check QuickLOAD’s output against reliable load data supplied by the powder-makers.

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https://www.accurateshooter.com/gear...ckload-review/

Update and clarification of a mistake in the data of my original post, I am 0.020 off the lans at 2.880. I looked in the bore this morning with the bore scope and see a tremendous difference in the throat and rifling. There is still some carbon in the grooves of my rifling that I have to work on tonight but I do believe although to be confirmed after cleaning and more shooting that my biggest problem is a very foiled bore. Rookie mistake right..... I can admit it!!!! I guess I’ve ever experienced this before and at least hope this solves the high pressure problems I’m seeing at the reduced powder charged loads. I’m still hoping someone can tell me an easy to find carbon cutting solution. I wore out 2 copper brushes last night.

The only thing I know of that will cut hard carbon fouling is GM Top Engine cleaner, or Mercury Qwik silver power tune. You will wear out several brushes when you are done. Patches will come out a muddy brown color. Finish up with JB bore paste.

Thanks for the info... do you buy the GM top engine cleaner only from dealer? Anything that can be bought at parts store?

Can't help with the GM Top Engine cleaner but you can get Power Tune at any Mercury Marine dealer or Quicksilver at any non-Mercury retailer that sells marine oils & lubes (WalMart, West Marine, etc). The stuff in the container is the exact same product (Quicksilver is Mercury's non-Mercury retail brand). ;-)

I finally got around to mixing up a batch of Ed's Red and I have to say it really does clean well.

http://www.beartoothbullets.com/tips...ve_tips.htm/53

https://www.brownells.com/gun-cleani...prod19936.aspx

http://www.gunsandgunsmiths.com/eds-red/

I bought some VFG pellets and a mandrel and combined with Ed's Red, it really stripped out the old carbon.

https://www.brownells.com/search/ind...lets&ksubmit=y

I’m still scrubbing out carbon and copper.... getting tired. Tried some GM TEC yesterday I found at Chevy dealer... must be a new formula as it didn’t work all that well. Trying some shooters choice black powder gel I got from a friend. Letting it sit overnight and will go at it again tomorrow evening. I also ordered some aluma oxide to try and make a Kroil mixture similar to Holland’s Witch’s Brew. I also have some J-B non bedding compound on its way. I’ll let y’all know which seems to work the best. Thanks again for your help on this pain in my *#%••.

Aluma Oxide. Almost sounds like a ceramic based abrasive like that found on sand paper, lapping compound and in grinding wheels called Aluminum Oxide.

You could check out "Slip 2000", another engine cleaning product that has been found to work well for removing carbon from rifle barrels.
I believe so much so the company has also started marketing other barrel cleaning products.
I believe you might find it listed among the cleaning products at Sinclairs.
I am always getting emails from them since I bought some from them a few years ago.