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NEED HELP!!!. Dont know where to start load development (signs of pressure at low loads)

Tonmarchelli

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Full Member
Minuteman
Feb 19, 2012
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Surprise, AZ
So im getting into load development for my rifle.

Caliber is 300 Win Mag

Rifle is a Remington 700 Sendero II bought new by Me, placed in an AICS chassis, with APA fat bastard and timney trigger, vortex viper PST 6-24 scope

Load is brand new Remington brass, CCI large rifle magnum primer, Hodgson H1000 powder and Hornady Amax 208gr bullet. bullets are seated .010 off the lands.

ive loaded rounds for it over the last year and everything ive loaded for it has shown a cratered primer. haven't seen flattened primers or hard bolt lift.

So today I decided to bring it back to basics. I started with the minimum recommended load from Hodgson of 71.9gr. and increased in 0.3 gr increments to 75.3 and went out to shoot. I shot all the rounds over the course of about 15 mins. shot at 100 yards at paper target. The rounds started about a full MOA left and Half MOA low. at the end they were A half MOA left and elevation was dead on. holding dead center from a previous zero.

the accuracy seems to be there. had 3 shot groups of about 3/4 MOA. but when i inspect the rounds. even the lowest powder charge shows some minor cratering. No flattened charges and no difficulty raising bolt.

IS THIS NORMAL!?!?!?! Im still a novice loader but how am i supposed to find the charge limit of my rifle if im showing signs of pressure the lowest recommended powder charge?

I want to get an OCW test going but i have no idea where to start with my charge. Any suggestions.

Sorry for the long post, just really confused at the moment.

Thanks. Heres a pic of the casings.
 

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You are most likely seeing the typical Remington 700 primer flow not actual cratering due to over pressure. As you noted, no heavy bolt lift, or flattened primers or ejector swipes. Google Remington 700 primer cratering for more details.
 
I had a similar issue with my 700 BDL 223 recently when I switched from 748 to AR-Comp to see how it shot. Groups got tighter, but it's cratering primers with absolutely no signs of pressure. Primers were CCI small rifle. My situation indicates a double pressure spike, with the solution, after much research, calling, and emailing is to try a few small rifle magnum primers.

I know you're already running magnum primers, but if you've got to option of trying another brand, it might be worth a try. Also, out of curiosity, have you tried and factory ammo to compare, as a baseline? It's a long road to get to where you want, but sometimes it's the best way.
 
I had a similar issue with my 700 BDL 223 recently when I switched from 748 to AR-Comp to see how it shot. Groups got tighter, but it's cratering primers with absolutely no signs of pressure. Primers were CCI small rifle. My situation indicates a double pressure spike, with the solution, after much research, calling, and emailing is to try a few small rifle magnum primers.

I know you're already running magnum primers, but if you've got to option of trying another brand, it might be worth a try. Also, out of curiosity, have you tried and factory ammo to compare, as a baseline? It's a long road to get to where you want, but sometimes it's the best way.

Please explain how you arrived at the diagnosis that you had a double pressure spike? You are talking a Rem 700, like the rest of us, and yet you have a different reason for cause.... What loads are you using, and how did you arrive at your conclusions? I doubt very much that you are correct, at least on the AR-Comp, as it was designed for AR's, so I question that it would be possible to load low enough to get a double pressure spike if you loaded within the ranges in the manuals.
 
wow, im the kind of person to research the crap out of things and I cant believe ive never heard of this. very interesting. Im inclined to believe you guys about the R700 cratering thing. makes the most sense. I guess with that being said, I am back to square 1 again on load development.

Where should i begin with my load development OCW test? Hodgson states maximum load to be 78gr H1000. So 10% off that would be 70.2gr. then add 2% per group of charges and work my way from there?
 
wow, im the kind of person to research the crap out of things and I cant believe ive never heard of this. very interesting. Im inclined to believe you guys about the R700 cratering thing. makes the most sense. I guess with that being said, I am back to square 1 again on load development.

Where should i begin with my load development OCW test? Hodgson states maximum load to be 78gr H1000. So 10% off that would be 70.2gr. then add 2% per group of charges and work my way from there?

My experience with H 1000 and 208 Amax in my sendero is a sweet spot at 76.8 grains. Do a search on the 208 Amax and H1000 you'll find a lot of guys finding their node somewhere in the 74 to 76.? Range.
Good luck let us know how it goes.
Ps don't worry about finding MAX load so much as finding that rifles accuracy node. Run a ladder test at distance using 74 to 77 grains and a crony. You'll find your node that is most important thing. Speed should wind up in the 2800 to 2950 range depending on your gun
Also my primers look like that outta my Sendero , FWIW
 
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Please explain how you arrived at the diagnosis that you had a double pressure spike? You are talking a Rem 700, like the rest of us, and yet you have a different reason for cause.... What loads are you using, and how did you arrive at your conclusions? I doubt very much that you are correct, at least on the AR-Comp, as it was designed for AR's, so I question that it would be possible to load low enough to get a double pressure spike if you loaded within the ranges in the manuals.

With 27 grains of 748, I've had consistent results with flat primers showing what I was taught as good pressure, no cratering or dimpled primers. When I switched to AR-Comp, the edges of my primers are still round, yet they are cratered. This to me says double pressure spike, because I have no signs of pressure at all. I've moved my charge all over the place, and can not get the pressures up where they need to be. After getting frustrated, I started investigating, and had several people mention trying small rifle magnum primers. I'm willing to try it, if for no other reason than experimentation.
 
With 27 grains of 748, I've had consistent results with flat primers showing what I was taught as good pressure, no cratering or dimpled primers. When I switched to AR-Comp, the edges of my primers are still round, yet they are cratered. This to me says double pressure spike, because I have no signs of pressure at all. I've moved my charge all over the place, and can not get the pressures up where they need to be. After getting frustrated, I started investigating, and had several people mention trying small rifle magnum primers. I'm willing to try it, if for no other reason than experimentation.

Not being an expert on the subject, all the reading and studying I have done on double pressure spikes has lead me to believe that said pressure spike happens when there is a small volume of powder in the case, allowing the flame from the primer to pass over the powder before igniting it. I have never heard of it taking place in a cartridge over 80% full of powder. Thus, I haven't ever heard of it taking place within the published charge range of a powder as listed in a manual or on a powder/bullet manufacturer's website in their official load data.
I have read and heard and seen "cratering" such as pictured by the OP quite often from owners/others familiar with Rem 700's, and many folks more experienced than I say it is from an "oversize" firing pin hole.
As a double pressure spike can be very dangerous under certain circumstances, I am definitely concerned about its actual existence. That is why I am questioning you more about how you arrived at this conclusion. While I do, however, doubt that you are correct in your diagnosis, I really would like to hear a second opinion on your data/cratered primers, as if you are correct, it is important to correct. I would like to learn more on the subject.
Can you provide any pics of your cratered primers?
Also, have you spoken to any techs at the powder manufacturer? They are most helpful in helping to diagnose these issues.
 
It has been reported that the flow around the firing pin is a design element to reduce leakage through the firing pin hole in the bolt face when a primer leaks. However if you don't like the looks, you can have the pin hole bushed to fit the firing pin tip more closely.
 
Try the 215M federal primers, that may be a solution, rather than rebushing the firing pin. Not at all unusual to see M700 primers like this. If you don't have ejector swipes, pierced or blown primers, you are not at max load yet.

Another thing - the latest .mil loads for the 300WM, use standard rifle primers, not magnums. They are Federal primers though,per the spec that was recently posted.

Wear your eye pro too!
 
Not being an expert on the subject, all the reading and studying I have done on double pressure spikes has lead me to believe that said pressure spike happens when there is a small volume of powder in the case, allowing the flame from the primer to pass over the powder before igniting it. I have never heard of it taking place in a cartridge over 80% full of powder. Thus, I haven't ever heard of it taking place within the published charge range of a powder as listed in a manual or on a powder/bullet manufacturer's website in their official load data.
I have read and heard and seen "cratering" such as pictured by the OP quite often from owners/others familiar with Rem 700's, and many folks more experienced than I say it is from an "oversize" firing pin hole.
As a double pressure spike can be very dangerous under certain circumstances, I am definitely concerned about its actual existence. That is why I am questioning you more about how you arrived at this conclusion. While I do, however, doubt that you are correct in your diagnosis, I really would like to hear a second opinion on your data/cratered primers, as if you are correct, it is important to correct. I would like to learn more on the subject.
Can you provide any pics of your cratered primers?
Also, have you spoken to any techs at the powder manufacturer? They are most helpful in helping to diagnose these issues.

I'm not in the least bit doubting I could be wrong. In fact, I've taken into account the possibility of a less the full case being the culprit. I'm having to relearn much of what I was first taught by my dad when I was 13-14 because some of it I began to question, and figured out it wasn't quite right. Now at 35, I'm discovering a lot of things I never learned. My 700 was new in 1993 I think. I'm wondering if possibly the firing pin hole on my rifle could possibly be smaller than current production rifles? It just baffles me that in the 19 years I've been shooting and loading for this rifle, I never had a problem until I moved away from 748.
 
Well, trying magnum primers surely won't hurt----you might need to back the load down a bit, because the primer flash will be greater, so the pressure could rise faster----suggest you start at the low charge and work up again to be safe.
How full are the cases now with the AR-Comp? I haven't had a double spike, as I tend to load powders that are often slightly compressed. But, as u said above, not being an expert by any means, I still question the double spike theory in a .223 with a powder that I understand to be made for these types of cases, and if you are nearly full, then the double spike theory is highly unlikely. I don't pretend to be able to definitively rule it out as impossible, but unless there is a lot if room in the case, I doubt it's likely hood.
Again, open to correction from more experienced folks who have the expertise I do not have.
 
As Sniper Uncle says, a light load of slow powder will do bad things sometimes. The phenomenon is labeled, "Deflagration to detonation", and will take a rifle apart. Hard to demonstrate on purpose, but has been done. That is why the caution about loading light with the slow powders available today.
 
Sniper, if I remember right, they are about 3/4 full. Not really enough to allow the flame to jump over the powder before ignition. So, I can all but totally rule that out. I'm on vacation right now, so don't have access to what the charge was, but I know it was near max according to Aliant's recommended data. I like the cleanliness of the powder, along with the consistency. For the sake of safety, I'm certainly going to drop down to the low end of the suggested charge, and only load a couple to see what results I get.
 
Sniper, if I remember right, they are about 3/4 full. Not really enough to allow the flame to jump over the powder before ignition. So, I can all but totally rule that out. I'm on vacation right now, so don't have access to what the charge was, but I know it was near max according to Aliant's recommended data. I like the cleanliness of the powder, along with the consistency. For the sake of safety, I'm certainly going to drop down to the low end of the suggested charge, and only load a couple to see what results I get.

Understand. There are varying opinions on this, but there are several sources that I have read/discussed the low volume fill/ larger volume case, including Gibb's, the master hand-loader who gave me basic training, and a book on internal ballistics, which have all indicated that if you are concerned about the low volume of powder compared to case capacity, then cream of wheat in its dried form can very safely be put on top of the powder to keep the powder against the case head---fill the case to very-very slight compression when the bullet is seated. This way, the powder is held against the head. This cream of wheat is inert, does not cause any ill effects in the rifle, and will remove any fears of secondary detonation or pressure spikes.
 
Understand. There are varying opinions on this, but there are several sources that I have read/discussed the low volume fill/ larger volume case, including Gibb's, the master hand-loader who gave me basic training, and a book on internal ballistics, which have all indicated that if you are concerned about the low volume of powder compared to case capacity, then cream of wheat in its dried form can very safely be put on top of the powder to keep the powder against the case head---fill the case to very-very slight compression when the bullet is seated. This way, the powder is held against the head. This cream of wheat is inert, does not cause any ill effects in the rifle, and will remove any fears of secondary detonation or pressure spikes.

You know, I think I've heard that mentioned, but never put much thought to it. But I really want to try that now. The helpful things we learn that are so simple, and get excited over. Haha You'd think after lurking unregistered for 2 years, and finally joining and getting involved, I would have learned by now that this isn't a flame fest forum.
 
I personally haven't tried the cream of wheat, as my powder choices/loads have much more frequently gone into 5-8% compressed loads, and I haven't had a very low volume load yet. But, if I were to try a powder/load that was rather low volume, I would not hesitate to try the cream of wheat given the sources I have had it suggested by.
 
The cratered primer is a typical Remington thing, now days. I see no other sign of pressure. If your primer flows outward and fills the crack around the primer or you get brass flow around the extractor, then I would back off. Lightman
 
It has been reported that the flow around the firing pin is a design element to reduce leakage through the firing pin hole in the bolt face when a primer leaks. However if you don't like the looks, you can have the pin hole bushed to fit the firing pin tip more closely.

Has anyone seen bolt faces with the firing pin hole chamfered, showing similar to cratering when pressure or type of primer is used.
CCI primers silver in color having a harder material than maybe Remington primers.