Quick load help

[Scrape hunter]

Was wondering if someone could run the QL for a load ? 100 gr. ttsx bullet, 30gr, of IMR 8208 xbr powder, cci 450 primer, hornady brass,18 inch barrel .2.200 C O A L.

[Klem]

Scrape,

That's a hot load: 63-64K lbs peak pressure plus 110% case full.

[VASCAR2]

Barnes online data shows 29.5 grains IMR8208XBR as a compressed maximum load with Barnes 100 grain TTSX, 2855 FPS with 24” Satern barrel. Minimum charge is listed at 26.5 grains IMR8208XBR at 2618 FPS with 100 gran TTSX. Barnes used Hornady brass with Federal 205 primer.

[Scrape hunter]

Getting good groups ,primers not flat ,very light ejector swipes , 2775 fps out of 18 inch barrel .I'm gonna run it , was hoping i could get a QL run on it .Klem no way this is 110% case fill ..

[grayfox]

I got very similar numbers to Klem's, >60ksi and >> 100%. His reply IS a QL run.
That MV is way too fast in 18" even too fast for my 22" and I shoot those ttsx's.
Just giving warning, as you requested.
You don't get high MV like that for free.

[biodsl]

I'm gonna run it

This forum can be so entertaining.

[Scrape hunter]

Well it sure isn't showing any signs of over pressure.

[grayfox]

Scrape,
You asked what kind of MV I was getting out of my 22" grendel.
I'm a bit hesitant giving strictly fps numbers out, especially since from your posts, I have the impression you might be trying to push a medium-pressure cartridge too far. Don't get me wrong, I like speed also, especially since mono bullets need speed to work their best, and I do like several Barnes's. For the 100 ttsx I'm now shooting mostly H335, but its performance is similar to Xbr, at least from my tests in my guns.

So let me offer first of all, some caveats. First off, the most important thing is what can your barrel shoot safely for you, irrespective of what someone else's barrel does. I always start with book data, and work up. Just because a book says so, doesn't mean that your barrel will respond the same. You could run into a max before you get to book max. Like Clint says, "a man's got to know his limitations."

You have an 18" barrel, I'm guessing it's an AR frame, since most bolt-actions either the poster will call it that or they are 20"+. So Saami limits to an AR frame is 52ksi.

The grendel doesn't show overpressure until you are already way over, so you can be over and brass etc doesn't tell you that. This is a key difference compared to other more standard calibers.

Also your post does not say whether you developed the load with benefit of a chrony, over a ladder of powder loads, so that's a flag to me that leaves me concerned too. Changes in MV vs changes in powder loads, And how they might accelerate as you approach or exceed max book load, for your barrel, are important trends to have for yourself, before you can adequately say what's going on with your shots.

Finally, I have gone over-pressure a couple times with the grr, but had enough info to see it and back off before I caused any kabooms. So I concentrate not on whatever max MV I can get, but what is a good and fast enough MV, on a NODE (ie, repeatedly accurate), under max, so I can shoot it and have an expectation that it will perform its job on target. I know this sounds like a lot of philosophical stuff but I think it is important to get out on the table.

My 22" bolt action rifle I can get 2725-40 fps on a node, with the ttsx, and that is admittedly over saami max of 52ksi but I have a bolt action, and it is below the 58ksi (est) that I stay under, for bolt action grendels. Thus it is still not a load to recommend for an AR frame, and I do not shoot that load in my AR frame grendels. This would translate to ~2615 fps (under 52ksi) in an 18" AR frame and depending on other specifics, such as using your OAL of 2.200".

What would 2615 ttsx MV deliver downrange? 1000 ft-lbs at 200 yds under nominal elev and temp conditions; and estimated 2162 fps, which indicate it would have an acceptable speed to open up properly in medium size game.

One more thing, I would strongly recommend that you pick up the Grendel handbooks, vols 1 and 2, from the vendor section on this forum (I get no $$ for saying this); they have a wealth of grendel specific information along with real gel tests and speeds of most of the useable grendel bullets, as well as lots of load data that some good grendel shooters got -- keeping in mind that your MMV. LOTS of good info.

I hope this is helpful. Shoot well and stay safe.

[Klem]

Scrape,

As the guys are saying, it is a QL run.

What is the point of giving you the predicted MV when the more important predictions of pressure and case capacity exceed safety margins? Plus it exceeds a manufacturer advisory. AR's are the canary in the coal mine for pressure, being relatively fragile when compared to stronger bolt guns. AR bolts will break sooner than bolt guns if you hammer them. May not happen on the first 10 or even 100 shots, but it will happen.

And as the guy's say, in Grendel when you see pressure signs on your cases, you are already over safe limits. Plus you are using 450's which are thick and strong. Signs of flattening/cratering will be mild.

You came here for advice but are fighting something you don't want to hear. If you want Creedmore get one in an AR10. Grendel is a 223 on steroids, nothing more - bigger bullets, more powder, but less pressure/velocity to keep everything from blowing up.

As for doubting the 110% case capacity, don't forget QL is predicting the available space after you have pushed a bullet into the neck to 2.200" (not the case being filled by itself). The base of that spitzer bullet goes a fair way into the case taking up room. Lead bullets of the same weight tend to be more compact, leaving more space for powder at the same OAL. If you want to use larger non-lead monoliths like Barnes there will always be less room for powder.

Predicted MV is 2,789fps.

Carry a spare bolt and don't shoot near anyone else.

[Scrape hunter]

well i worked up off a ladder from 28 grains and never once seen a spike to 30 grains but watched groups get smaller as i went up .I haven't loaded up a large quantity yet just wanted to see what kind of pressures i was dealing with was the reason i asked for a quick load info. Klem not trying to beat my gun up or myself just wanting to get all i can accuracy wise and performance wise also .I will back it off to the 29.5 barnes recommends knowing full well 30 grains is safe in my gun .Thanks for your help with this matter much appreciated .Scrape hunter

[Klem]

Scrape,

All good, but the advice to carry a spare bolt with AR Grendels is sound, not sarcasm. It is easy to stray into over-pressure and in your case group size is the motivator. The likely part to break is the bolt and if you think of this as a consumable item like barrels then it may be cost effective to replace bolts every few thousand rounds whether they break or not. Like aircraft parts are regularly replaced. As long as you accept the higher risk of getting hurt and don't drag anyone else into that risk.

On the Forum, those willing to share info about this always report a bolt lug or two that breaks off. Bolts appear to be the weakest link in the AR pressure vessel. No doubt there are more bolt-breakers who might be too embarrassed about sharing this info. In the early days I broke a piece of bolt lug off, using a bolt with a notch in it designed to share pressure opposite the extractor. If I had it handy I'd post a photo. Point is, I didn't know it was broken until cleaning the gun later. Swapped it for an AA 'Hard-use' and keep it in the butt as an emergency spare. I'll replace the bolt eventually, probably when the barrel gets changed.

[JASmith]

Well it sure isn't showing any signs of over pressure.

What are the overpressure indicators that you are looking for?

We don't see the classic indicators of overpressure - flattened primers, etc. - until well pressures are well over 55,000 psi.

With a SAAMI max pressure of 52,000 psi and a recommended max operating pressure of 50,000 psi, overpressure indications are difficult to detect in the Grendel.

[jasper2408]

My version of QL uses 37.50 grains for the default value for the case capacity for 6.5 Grendel. Now I don't always use it as it can depend on the bullet-powder combo that is being entered as sometimes I use the actual case capacities (35.6 Starline & Hornady, 35.9 lapua) to get things to line up.

Anyway, if I use 37.50 as the case capacity, in this instance, then the numbers from Barnes load data line right up and the pressure is 51434psi in QL. I am using the 2.235" COAL and 1.506" case trim length from Barnes data. Everything is fine pressure-wise for 29.5gr of 8208 but 30gr is over by about 2800psi. Now, if I leave everything the same as Barnes but change the COAL down to 2.200" then I am over-pressure again by about 1700psi. Changing the case length from 1.506" to 1.510" doesn't put me over-pressure but it does raise the pressure by about 200psi.

I also tried these settings in GRT but I could only go up to 29.0 grains of powder before it showed over-pressure.

Edit: changed QT to QL. Brain fart. Thinking of Quick Target I guess.

[VASCAR2]

If you use the google custom search feature for the 6.5 Grendel forum linked below you can look at threads discussing broken bolts. One of the most common powders where 6.5 Grendel bolts broke was using IMR8208XBR. In one instance a forum member was using 107 grain SMK with a load of IMR8208XBR with a below max load. This member broke a couple of bolts with this load. It was possible the upper receiver and barrel were not square which put additional stress on the bolt.


Another common issue with the 6.5 Grendel is where manufacturers don’t replace worn cutters which result in short chambers. An out of spec chamber and/or over gassed barrel are recipes for breaking extractor and/or bolts with max loads with the 6.5 Grendel.


I’ve broken one extractor on an over gassed 6.5 Grendel but I keep spare extractors and bolts for my AR-15. I fixed my over gassed 6.5 Grendel with a Rubber City Armory adjustable gas carrier key.




https://cse.google.com/cse?cx=0163689474...cu1o&hl=en

[Scrape hunter]

Jasper could you run this @ 29.3 with c o a l. set at 2.200 would be much appreciated?

[Klem]

Jasper, my version of QL has Grendel default case capacity as 35.99gns.That's a big [dangerous] difference between mine and yours. I have sealed and weighed Lapua cases as 35.13gns new unused, and 35.92gns used and FL sized. I only use the default when estimating loads for others. My QL estimates 28.2 as hottest safe load for Scrape. If a manufacturer recommends more then all good, QL is notoriously conservative.

Scrape, seeing you are committed to loading hot why don't you determine the case capacity of your own cases for safety. Seal the bottom with Blu-tac or a spent primer and fill with water - weighing the water by weighing empty, and weighing full. Do this a few times to get a reliable average. Pressure estimates will be more precise.

[jasper2408]

Jasper could you run this @ 29.3 with c o a l. set at 2.200 would be much appreciated?

For 2.200" COAL and 1.510" case length I am showing 52208psi which is still over pressure. I do not recommend this load. I would recommend using the Barnes load data.

I have to get this out of the way.
Disclaimer: Do not use any load data that is developed with Quickload. The loads are dangerous and unsafe and could blow your gun up in your face resulting in bodily injury. I do not recommend using any load developed using Quickload.

[Klem]

Jasper,

If you think Grendel has 37.5gns of case capacity then I don't doubt your 'disclaimer'. Have you measured your own cases yet?

QL has always worked for me, when appreciated as a computer prediction only, and considered alongside manufacturer tables, and the experience of myself and others. I find it invaluable.

Both of us can't be right.

[jasper2408]

Jasper, my version of QL has Grendel default case capacity as 35.99gns.That's a big [dangerous] difference between mine and yours. I have sealed and weighed Lapua cases as 35.13gns new unused, and 35.92gns used and FL sized. I only use the default when estimating loads for others. My QL estimates 28.2 as hottest safe load for Scrape. If a manufacturer recommends more then all good, QL is notoriously conservative.

Scrape, seeing you are committed to loading hot why don't you determine the case capacity of your own cases for safety. Seal the bottom with Blu-tac or a spent primer and fill with water - weighing the water by weighing empty, and weighing full. Do this a few times to get a reliable average. Pressure estimates will be more precise.

Sorry Klem I did not mean to offend you.

How am I being dangerous? I am not recommending any loads except the Barnes book data. I told him that he was over pressure on everything but just not as much as you told him that he was over pressure. My data in QL lines up with the Barnes data using the same specs as Barnes does. Barnes doesn't show psi data so I used 52000psi as the cutoff in QL. I also showed him what changing COAL and case length does to pressure.

As far as the 37.50gr case capacity goes, I did not just make that number up and just put it there because it sounds good. The people from Quickload put it there as the default. I didn't have anything to do with it. I also stated that I could not use that number in all calculations and that I had to use actual case capacities on some bullet-powder combinations. I also gave those case capacities by brand. I always try to get QL to line up with the book data first. You can change anything in QL to get it to line up with the book data. I have seen people change the powder burning rate factor(BA) or the Weighting Factor but I don't change any of that.

Edit: changed QT to QL. Brain fart. Thinking of Quick Target I guess.

[Scrape hunter]

No need for anyone to get offended just asked jasper to run some #'s for me nothing more nothing less .The only thing that concerns me with 29.5 grain load is my seating depth, and i can see where this could be a pressure maker .I talked to the technicians at barnes bullets about there load data today they assured me this load was under 52000 in there tests .They also said they would never publish any load for anything that was over saami .