Blocked bolt with reloaded ammo

[Dean2]

Based on your pictures, even though they aren't real clear it I am pretty sure you are over pressure. If brass takes a while to cool down before you can extract it that is another pretty good sign the load its too hot, as is the fact it doesn't do it with factory ammo. Now you have to determine if it is bullet seated too far out, too much powder, neck not having enough expansion room in the chamber, make sure the bullets you are using measure .308, I have seen packaging errors, too hot a primer or the lower capacity of the Privi case. Great brass but typically heavier and holds less volume than WW or Rem.

DO NOT shoot any of the loads that are sticking!. If you are going to keep loading buy even a cheap chronograph. It is the best pressure gauge the average reloader can get. Velocity basically equals pressure. I have reached max velocity many times before I ever got close to max published loads, I have also seen the reverse.

 

[CVCOBRA1]

Where are getting your load data info? From a manual? Off of the internet?
You say you "think" the max load is 45g. Don't "think"----verify.

 

[CVCOBRA1]

What country are you in?

 

[lyle2231]

USA

 

[Jeffrey Van Zandt]

good read on pres https://www.primalrights.com/library/articles/understanding-pressure

 

[Jeffrey Van Zandt]

is it a factory Remington 700 ? just cleaned up one yester day that was so ruff any fired factory ammo would not come out with out a fight works well now for the shooter

 

[Praire Dog]

if not overloaded; could be a dirty chamber preventing easy extraction. could be brass too long and needs trimming that is creating an overpressure situation, hot load, or all of the above.
I have not seen reloder swiss powders offered for sale here in the usa. their website didn't show a sierra 175hpbt...… my guess would be that you are pushing max pressure @44.8.

might start from a fresh beginning; with cleaning the barrel and chamber, clean brass (tumble and or wipe down with alcohol), resize, clean brass again, trim to correct length, start load work up at 42 and work up in .3 gr increments.

In fact that is what I did. In my first try, I reloaded with .3 gr increments from 42. But my best groups were with 44.4 and 44.7 gr. So in my second try, I reloaded with 0.1 increments from 44.3 to 44.8
I found a good group of 0.4 MOA around 43.5, but around 44.7 I got almost 0.2 MOA. The rest of charges were not very good.

I looked for the max charge in the website of the manufacturer, but they only had information for the following:
-Sierra HPBT 150 gr--> Max load: 47.4 gr
-Sierra HPBT 168 gr--> Max load: 46 gr
-Sierra SBT 200 gr--> Max load: 42.7 gr

So I interpolated the result.

 

[smokey3]

I had this problem once 6.5-284, thought I had overloaded, but only did it with Hornady brass, no more hornady, no more problem.

Technically speaking, you did overload if only for that particular brass.

 

[jreagle]

assuming the manufacture of the rifle is good and your brass is prepped; sounds like your rifle is telling you that 44.8 is over pressure with your brass bullet and rifle combination. back off a few tenths of a grain, shoot it, and if no problems, that would be your max. allowable load.
reshoot up to the new max and find your best group from there.

need more velocity; use a lighter bullet or try lapua brass or try a different powder. if the rifle is brand new; velocity may speed up as the barrel breaks in..... and then the hot load will most likely not group anymore.

as previously mentioned, a chronograph while developing loads may help to better know when you are approaching high pressure; velocity will jump up in a larger increment. you can identify the velocity of your accuracy load which will help as you change powder and primer lots.

don't use the RS50 44.8 or 44.7 load in your current brass, bullet, rifle, load combination; the next time could be a disaster. note it in your load book that it is over pressure and dangerous.

as an example; my 308 seems to reach pressure before max listed loads; my tightest groups are about a grain below listed max.

 

[Frog4aday]

It sounds like you did your due diligence, but your gun is telling you it isn't happy with the load being used. Heavy/hard bolt lift is a 'sign'. You know it, too, which is why you are asking. As others have pointed out, your load MIGHT be okay in thinner/lighter brass (with more INTERNAL volume), but the PPU brass seems to be thicker and heavier (akin to 'military brass') which normally requires a 5% reduction in charge to maintain safe pressure levels.

Also, the data you are using isn't showing the bullet you are using, so you are extrapolating (which we've all done at some point) and that's fine if your gun wasn't "complaining", telling you it isn't fine. And without a chronograph, you really are 'guessing' at things right up until your bolt no longer wants to open. And that's over-pressure. Bad for you. Bad for the gun. Bad for the people shooting next to you at the gun range.

You can get a good chronograph for $99.08 on Amazon (google: Competition Electronics 538002-SSI ProChrono Digital Chronograph)

For those that are curious, here is the load data from the powder manufacturer:

 

[nevada75]

Using PPU brass in a single shot 30-30 and in a bolt action 22 hornet I had excessive pressure show up well before I reach max powder charge. I was using published data from Hodgdon's website cross checked against various reloading manuals (Speer, Sierra, etc).

I weighed the PPU brass along with somesome o measurements and compared to Remington and Winchester brass I had. The PPU brass was consistently heavier. I don't have my notes handy but think they were maybe as much as 3 grains heavier on average.

I concluded the the brass is just manufactured heavier and thus less internal capacity. I decided to use the PPU brass for low pressure loadings with cast bullets.

 

[Dean2]

Using PPU brass in a single shot 30-30 and in a bolt action 22 hornet I had excessive pressure show up well before I reach max powder charge. I was using published data from Hodgdon's website cross checked against various reloading manuals (Speer, Sierra, etc).

I weighed the PPU brass along with somesome o measurements and compared to Remington and Winchester brass I had. The PPU brass was consistently heavier. I don't have my notes handy but think they were maybe as much as 3 grains heavier on average.

I concluded the the brass is just manufactured heavier and thus less internal capacity. I decided to use the PPU brass for low pressure loadings with cast bullets.

I have used a lot of PPU brass from 22 Hornet all the way up to big magnum. It is heavier and it does have less capacity. It will also produce top velocities at much lower powder charges and it lasts **** near forever. I have some PPU brass for the 22 H that has never been annealed, has over 25 firings on them and produces 3100 fps with a 40 grain Vmax and 12.6 grains of Lil'Gun. I need over 13 grains in RP brass to get the same speed. It is excellent brass but you do have to adjust your charges to compensate.

 

[Praire Dog]

Well, all of you agree, so I will try new loads around 43.5 and we will see. If it doesn't work, I will have to go under 42 gr.

 

[CVCOBRA1]

Start high and go low.....?????????????????