I have had some problems with using quickloads with my 700WTF. When I first started reloading it I made some jacketed bullets from swaged copper pipe caps that weighed around 650grs. quickloads said that 185grs of 4198 was good and should have been around 40,000 psi, well it was not. It locked up the bolt and when I finely got the bolt out the case was stuck in the shell holder. I got it out and measured it and the case head had expanded around .03 and the primer was cupped and very flat. I am wondering if any of you have noticed any problems with large straight wall cases and quickloads. Thank the lord i was not shoulder firing, it was string fired.

here is a pic of the case that took the beating of 185grs of 4198

QL is known for having problems with very large and very small cases...plus you have to include the variations for straight walled cases, bullet metal type and seating depth...they can affect pressures in very dramatic ways...Call Ed to get that stuff sorted out.

Question; Did you have the bullet seated off the lands or into the lands, what case capacity, shot start pressure, and weighting factor did you use...per chance?

I ran your data to see what the pressures were and came up with ~35KPSI for the 185gr/748/1132 gr cast lead load. I'm certain you know that you can get much higher velo with cast that with jacketed so maybe the Jacket had something to do with it...

The same 185 gr 748 with a jacketed bullet came up with 2530fs and 28587psi... but 2929fs and 50230psi with 185 gr IMR4198...I used .75 weighting factor, 6525 short start pressure and 282 case volume...7% additional case volume for the straight walled case.

I use Load from a Disk, QL, Powley online computer and lots of reloading manuals and wildcatting books...check and double check and always use the "string method" for the first shot.

Luck

Looking at that primer and knowing how thick the metal is on a 50bmg primer, you must have been north of 70K psi on that one.
I'd say that Proofed it.

Cheers, John

part of what quickload uses is starting pressue, or bullet sticktion.....

FWIW- I'm sure your aware that Shellholder actions have no camming action to assist in opening. You will not be able to run the pressures you can with a Mcmillan action for example. Because you won't be able to get the cases out of the action. My first competition .50BMG was a AMAC 5100 shellholder and it locked up solid on loads I could easily open with my Mcmillan. We ran the .50BMG's very hot at over 65 KPSI to beat the wind drift.
I've had no problems with Quickload in any of my .50BMG cases although I also start 10% low from any Quickload predictions and work up from there. Sticky cases in the .50bmg or bigger are the best indicator of high pressure. The primer appearance is not a reliable measure, but if your primer pockets are opening your probably above 65 KPSI. Stop when extraction becomes at all sticky and move back 3%.
What bullet jump are you using between the case mouth and the throat? Make sure your bullets are not in contact with the lands and you have at least 0.005 clearance between the case and chamber wall with a loaded bullet in your Case. This is critical!!!!Give the bullet at least a 0.030 jump. Finally, make sure your bullets are no more than 0.0005 over average bore diameter too. Many big bore bullet makers actually make them intentionally slightly undersize. If the bullets are only a little oversize,pressures go up dramatically. -Rob

thanks Rob, I will dig up my chamber drawings and let you know what the mesurments are. I know there is about .05-.01 for the case to expand at the mouth with a seated bullet. i gave it a long throat so i could load super heavies. but let me dig up my drawings and i will let you know.

Combination of things, Those jackets filled with lead
from the rear may expand a little.They do not have rolled
edge on the bottom covering part of the base like
making them with Corbin dies.

Powder, better off using ball or Alliant.
Using 4198, it is real quick, time wise, in starting and
getting to peak pressure, say compared to H335, etc. which
is similiar overall rated speed. And as Rob says
no primary extraction. I only use 4198, 4227, for ultra
light bullets. Ed

Gotta agree with Ed. It sounds more like a combo of non-optimal powder ( maybe too much, but I don't think so) and a slightly oversized bullet. I found that as little as 0.0007 oversize caused pressures to go up dramatically. Sounds like you have a ton of clearance between the chamber wall and the loaded bullet/case which is a very good thing. Same for long throat! I am also very partial to RL-19 and 22 and H335 in these big cases. Start low and work up though and feel for sticky bolt lift!
I also am very partial to Bore-rider designs on my bullets as another way to keep pressures down and get a easy 150fps over conventional bullets.
The good news about shell holders is the cases will stick solid in the chamber well before you get into major pressure problems.With your tight shell holder to rim specs, once that case sticks, the brass has no where to go except back and getting it out of the shellholder will be a problem. Thats also the danger in the McMillan style actions. Everything looks fine till the whole thing goes!
If you can find some IVI or recent LC brass it is better than PMC too. Stay away from once fired Machine gun brass. Only use new stuff. You might also uniform the case wall of your cartridges before you load the bullets for a better more uniform release. Those cases usually are pretty gnarly, meant for machine guns not precision rifles-Rob

i just got 320 rounds of once fired WCC brass made in 2007. great looking stuff and very clean. here is the drawing of the chamber, its designed so i could set the barrel down till it touched then top of the bolt and there would be .010 gap from the end of the case mouth to the end of the chamber. with a 3" shell in the bolt the case sticks out from the end of the bolt 2.84". i have the barrel set about .01 off the end of the bolt to prevent binding. here is the auto-cad drawing of my chamber.

JT-What is the diameter of a loaded case with bullet seated just off the case mouth? Those cases probably are not totally uniform so look for the widest measurement. At .750, I'd think you would be just fine and with a 0.010 gap between the case mouth and a .702 leade you should be just fine. As long as you have at least 0.005 clearance between the loaded case and the wall you should be OK. What bullet diameter are you averaging, .7000 OR what? You might try the same powder load and a .7000 Brass bullet and see if it sticks again. Then you'll know its the bullet or the powder.-Rob

a loaded round measures about .744 at the mouth. all the brass i have checked is .02 wall thickness and very even around the mouth. Right now i'm paper patching lead bullets. and most of the time thy end up being just about .700 some times .699 but its hard to measure paper. I measured a fired case at the mouth in the same spot as the loaded round, the fired case is .01 larger in diameter. so the brass is able to expand .01, i wanted to make sure i had enough room for the brass to expand because i was going to be using surplus brass and i could not count on even case wall thickness.

JT- Sounds like enough clearance all around. Remember though, no muzzle brake on PP bullets. I make mine from dead soft lead and 0.003 paper with moly disulfide coating on the paper. I actually try for 0.001 oversize on the PP bullets. Never on Brass solids though! I've had good results with PP bullets but would never run them through a brake. I still think your bullets expanded too much at the base and that combined with a peaky powder caused your sticky cases. Try Rl-19 or H335 and some brass solids. I'll bet it works fine for you. If you get sticky bolt lift, then just keep backing off till it goes away.
I'm just trying to help you and if any comments come out too gruff, it's not my intent. I've been through similar issues before. These cannons can be a steep learning curve. I wish you only the best.-Rob

i have nothing but lots of thanks to you for your help. Ed also helped em a lot over email. i have some h335 for my 50 that i might try.

JT- Isn't the bore diameter on your .700 barrel .688? What is the .680 dimension on your drawing?Isn't it the bore diameter? It's been so long since I worked on the .700, the details escaped me till last night. I checked my barrel specs and they are .700 across the grooves and .688 bore( across the lands). 0.006 deep lands are good for large bore solids. I suppose that .700 barrels are not really standardized, but thats more of a squeeze down than I used in my .700. As I remember I got my specs from H&H. Unless thats an error, you may have a very tight barrel at least compared to mine.! Who made your barrel? Probably would still work fine with short cast bullets, but pressures would skyrocket with long solids.A bore rider would be Ok though.-Rob

krieger made my 700 barrel. Yes its a 700 nitro express barrel. I drew the throat at .680 because I cut the chamber with a boring bar on the cnc lathe. I wanted the tool to go smaller then the bore so I had a nice smoothed throat.

Jt- Ah, now I understand what you did. I was concerned that your barrel might have been made with a .680 bore.Stranger things have happened. Was it a .688 bore?
I used a reamer on mine and didn't bore the chamber. Still,I would have just cut down from .7020 to .700 in .5 inches and then to .685 with a 3 degree per inch internal taper with the biggest 6" or more carbide boring bar I could get into the bore. You should still be in no more than 4.0 with the completed chamber, right to the .688 bore diameter. There is always some spring to even a carbide boring bar so did you make a cerrosafe cast to see how it came out?-Rob

I used a borematic to mesure the diamater of the throat, but no I did not cast it.

I'm wondering about using Trail Boss in this large of a calaber. I would like to find a good mild 1500fps load for hunting and thought trailboss would be nice. Any ideas? I have 8lbs of AA 8700 that I thought I would try. I'm heading to a gun show this weekend quad a good powder to play with?

well I tested the 8700 and trail boss loads as well as some w748. the 70gr trailboss loads pushed the 1132gr bullet to 1200fps. the 200gr 8700 loads did 1350fps. And the w748 192.5gr did just a hair over 2000fps.

Jt- yes 8700 and trailboss are too slow as is H50bmg. WW 748 works well and burns well in short barrels. What weight bullet did you use?-Rob

I was using the 1132gr bullet for all loads.

Sounds like a good load. Ball powders in general work best in these big cases. I'd go up till you get a trace if sticky bolt lift then back up a tad. See what velocity you ultimately achieve. -Rob