Home Forums Reloading Reloading Software Would like Quickload IMR8208 data

Hey guys.
Would like some data. I loaded some 50gr Barnes ttsx over IMR 8208. Am wondering if the program thinks I'm getting close to max load. No sign of overpressure so far. Here's what I got:

Bullet is 50gr TTSX (Similiar to 50gr TSX), overall length 2.204". Rifle is Remy model 7 with 18.5" barrel.


24.9gr IMR 8208, velocity 3091 and 3073.
25.1gr IMR 8208, velocity 3130 and 3128.
25.3gr IMR 8208, velocity 3130 and 3102.

What cartridge?

That would be .223

Adjusting the weighting factor to correlate with your indicated speeds the 25.1gr load goes 56,663 psi.
The 25.3 load runs 58,188.

Thanks for that. I don't plan on going up any more, but I have easy bolt lift, no extractor marks, etc. But would you guys consider that the absolute upper limit? These are mono copper bullets.

Another thing I neglected to mention that the Chrono was 5yds from the barrel, so the mussel velocity should read 3150fps. I suppose that further increases the pressure, eh?

A more accurate estimate can be given if the actual case capacity in grains of water is known.

I think you still have room to work pressurewise but you'll be running even more compressed loads.

It's Winchester brass, 30.2gr of H20 capacity. Shot some groups with 25.2gr load, very poor, around 3".

With a capacity of 30.2 gr [bleep] gets really interesting.

How does 27gr of 8028 running 59,821 psi and pushing the 50gr TTSX to, get this, 3342 out of your 18.5" tube sound?

You're at almost 109% of capacity though so you're running pretty compressed.

So you think i have room to play with? But how close to real world is that Quickload data?

I was aiming for 3200fps. I wasn't able to find any tsx with 8028 data, so I just did some cross referencing and came up with that # myself as being close to max safe load velocity.

The Hodgson data website shows a 45gr Sierra Sfire (i believe solid copper) bullet being driven at 3490fps out of a 24" barrel, OAL of 2.220, using a 26gr compressed load, at 52,100 PSI.

Don't know how that translates exactly to the 50gr TTSX. Does Quickload make sense with the above?

I haven't noticed any visible high pressure signs. The primers are fairly flattened, but I'm using Winchester, which are supposedly softer that others.

You have room pressurewise but not capacitywise.

So suppose i increase the OAL to say 2.220". What'll that do to the pressure when using the same powder weight? Also, wouldn't seatIng closer to the lands increase pressure?

Got some more info. The bullets engage the rifling at an OAL of 2.232".

Looks like I'll have to seat them deeper in the casing (Barnes recommends seating between .030 and .070 off the lands). So, if it's already a compressed load, I presume seating even deeper, say at OAL of 2.185, will not increase pressure, eh?

What velocity and pressure do 25gr 8208 and OAL 2.185 give you?

Many Barnes users run them right on the lands despite Barnes' recommendation.

The numbers come up 49K and 3069.

26gr gets 55.6K and 3198. But at 105% fill.

25.2gr of 8208 with OAL of 2.182" (.050 off lands) gives me:

3130fps, 3105fps,, and 3120fps at the mussel.

2 bullets were touching, other was 2" straight down.

Can QuickTime do that time in barrel calculation and predict at what time the bullets leaves the barrel? I'm thinking of that theory where guys find an accuracy node by having the bullet exit the barrel at a time when the vibrations created by ignition have traveled from the end of the barrel back towards the action.

Chris Long's Optimal Barrel Time hypothesis? QL and a chronograph are used to help with that calculation, yes. I have used it for that purpose myself, in fact.

As a suggestion (in case you're not necessarily a gadget freak, or have a limited budget), try this:
http://optimalchargeweight.embarqspace.com/
I have found that to be dramatically faster & more efficient at finding an accuracy 'node' for what I want from a rifle.

Yep. That's what I'm referring to. What I'd like is what that theory thinks are the accuracy nodes. Here's some info:

Remy model 7 bolt .223 with 18.5" sporter barrel.
Winchester brass 30.2gr H2O capacity.
IMR 8208 and 50gr Barnes TTSX.
25.2gr of 8208, OAL of 2.182" (.050" off lands) giving you average velocity of 3115fps.

The barrel time nodes for Chris' hypothesis are on his website:
http://www.the-long-family.com/OBT_paper.htm

For the estimated/predicted barrel times of your load and rifle, you'll need to buy QL, and probably a chrono.

Got the chrono but no QL, so need someone to run the numbers for me, kindly. From Chris' paper, my OBTs are:

1) 0.628ms
2) 0.700ms
3) 0.785ms
4) 0.858ms

Unless I didn't calculate correctly, that doesn't look like a linear relationship.

It is not linear. I don't recall Chris' proposed explanation for the non-linearity just now, nor for certain whether he has a proposal, but it may either be on his site or at another he used to frequent.

For the load you specified the barrel time is .848ms.

25gr even gets you .858ms.

Thanks for that. Will check it out.

I presume the next node up would be over pressure. A quick guesstimate says around 26.4gr, eh?

Not over pressure but you're getting to nearly 108% fill.
26.5 is .787ms 26.6 is .783ms.

At 25.2 grains i can still hear a little bit a powder shake, so that's not yet at 100% capacity. How much can you compress in these small cases?

Also, at what psi is considered over pressure?

SAAMI MAP is 55,000

CIP MAP is 62,366

I've been using CIP.

I don't know about the compression question in the .223 case.

Can this data be extropopated to get velocity / pressure of OBT from other powders? Mainly interested in IMR 4895 data.

I'd be looking at H335 or Ramshot X-terminator.

Much higher velocities and much less compression.

This is being used in extreme conditions. Coyote calling, 25F Below in winter, and up to 70F Above in fall for deer. Am using only 1 load for all. That's main reason i'm using imr 8208, has very little fluctuation. I'm open to other powders, but has to be an Extreme powder.

With 50-grain bullets _in general_ I've had good results with IMR4198. The 4198s (Hodgy-branded and IMR-branded) are both advertized by Hodgy to be extremely temperature stable. At this point, they're both Thales powders out of Australia, but I don't believe data is interchangeable. I don't shoot Barnes bullets, however, so I don't have experience with that specific combination.

Back from the range. Don't look very good. 25gr 8208, OAL 2.185.

Velocity: 3054, 3063, 3097, 3037 (avg 3062fps). Was a 2.25" group.

I know this rifle is capable of doing much better (it consistantly shoots 1/2 groups with 40gr Bergers). I think I may have a stabilizing problem with these Barnes loads (barrel is 1/12 twist). What do you guys think?

I'm using a faily thick plastic walled pail as backing for my target. I haven't noticed elongated holes, but what I have noticed is that the bullet tips are buried in the plastic beside the exit hole.

So how does one find out if the bullet stabilizes? Would shooting at 200yds tell me more? Also, would cold weather compound the problem?

If you have marginal (or insufficient) stability, then everything that increases air pressure/density will make the issue worse, such as colder temps, lower elevation, or higher barometric pressure. Yes, taking them out to longer range will help you see whether they're stabilizing adequately or not.

Barnes' low-density bullets (any all-copper bullet is lower density than a lead-cored bullet) are longer per weight than a 'regular' bullet, and length is the primary factor in what twist rate you need for a given projectile. If you'd like to take precise measurements of the length of your exact bullets, you can plug that and the velocity into one of the calculators on the JBM Ballistics page and it'll calculate stability for you. IIRC, it just gives you a number. Whether that number is 'enough' is something you have to proof on-target.

Will have to give up with these. Another round with 3" groups. OAL 2.192, 25.5gr 8208 at 3162fps.

Quickload; What pressure and velocity #s do 21.1gr of IMR4198 at OAL 2.185" give?
Am also going to try some Benchmark.

48.5K and 3080.

What do you guys think of the primer on the left? It's from the 21.1gr IMR4198 load mentioned above. The casing on the right is from the above mentioned 25.5gr IMR8208 load.

Is that a cratered primer on the left? I hit my chrono with that round, so didn't get a reading (it'll still work though:). The right casing has a nicely flattened primer; the one on the left is still really rounded on the edges, but there is a crater around the firing pin hole. It's visible, and the ridge gets your fingernail caught when sliding over it.

Am wondering if it tells me anything.

[img]http://pbckt.com/pE.OlbzP5[/img]

[img]http://pbckt.com/pE.OlbahN[/img]

Cartridge on the left saw less pressure than the one on the right, IMO.

Agreed.

Benchmark is next. What numbers do 25.6gr at OAL 2.205 give?

Gonna give these bullets one last shot with this combo.