Find the lands (jam point) in semi automatic

[AbeS]

I’m very interested to know how the experienced get their coal. I have managed to get a sd of 8 for my browning bar in 30-06 but the 5 shot group was weak (1.5moa) and I loaded to magazine length or 0.010 shorter than magazine length I should say. I tried to figure out my jam but i just can’t do it with the bullet in the fired case method ( crimping nek with pliers as I don’t have mandrel die) figured I want to fit in the magazine anyway. Would you seat deeper or go longer than mag length? ( I know longer is not ideal but I’d rather load one a time and have the accuracy than be able to load more with less accuracy) if longer how can I get the jam (tight in the lands) for my browning mkiii

Thanks

I don’t know if it’s worth mentioning that I’m right on the saami spec max length

 

[Ccrider]

Not being condescending, but I strongly suggest that you find an experienced reloaded around you and ask for help.

 

[GLShooter]

The Hornady tool designed for semiautos will fill your needs.

Greg

 

[AbeS]

The Hornady tool designed for semiautos will fill your needs.

Greg

Found the part numbers thanks! Will see if scheels can order me one

 

[Bc'z]

I’m very interested to know how the experienced get their coal. I have managed to get a sd of 8 for my browning bar in 30-06 but the 5 shot group was weak (1.5moa) and I loaded to magazine length or 0.010 shorter than magazine length I should say. I tried to figure out my jam but i just can’t do it with the bullet in the fired case method ( crimping nek with pliers as I don’t have mandrel die) figured I want to fit in the magazine anyway. Would you seat deeper or go longer than mag length? ( I know longer is not ideal but I’d rather load one a time and have the accuracy than be able to load more with less accuracy) if longer how can I get the jam (tight in the lands) for my browning mkiii

Thanks

I don’t know if it’s worth mentioning that I’m right on the saami spec max length

You answered your own question.
Knowing longer isn't ideal, definitely push the bullet deeper into case.
I like moving in .003 increments.
Load all round at best charge weight
Adjust seating in 3 round sets to be shot for group.
Seating nodes will roll in and out.
Once you find your optimum depth load on the front side/shortest depth to compensate for throat erosion yet maintaining accuracy.

 

[AbeS]

You answered your own question.
Knowing longer isn't ideal, definitely push the bullet deeper into case.
I like moving in .003 increments.
Load all round at best charge weight
Adjust seating in 3 round sets to be shot for group.
Seating nodes will roll in and out.
Once you find your optimum depth load on the front side/shortest depth to compensate for throat erosion yet maintaining accuracy.

Great answer thanks

 

[std7mag]

I'm not sure how your BAR is chambered.
Meaning normally a semi is long throated.
Old trick used by manufacturers to help keep pressures down.
While you can single feed it, i'd probably stick to fitting in your magazine & find a bullet that accepts the jump.
Sierra GameKings, Hornady, Nosler Ballistic Tips i've found to be very jump tollerant.

 

[jepp2]

Make sure you are running plenty of neck tension. In my BAR the bullets moved forward during chambering if I didn't run enough neck tension. Easy enough to check. If they are moving your COAL will be different for every round fired.

 

[NorCalMikie]

IMHO, you damn sure better know what you're doing when it comes to "jamming" bullets in a semi auto. If not, you're just asking for trouble!! Only takes one time with a slam fire to REALLY open your eyes.
I HAVE neck sized and loaded rounds to an OAL that jammed the bullets in my M1A but, I single fed so I knew what to expect.

 

[Coyotefurharvester]

I don't know why you would want to shot single shot(loads longer than mag length) with a magazine hunting rifle. Follow Bergers seating depth test starting 0.010 under mag length, sized brass necks 0.003-0.004 under the loaded round neck diameter. Don't make things anymore difficult, accurate powder charges with correct powder for cartridge and bullet, seated for function then accuracy.

 

[bozo699]

AbeS,
If you have single digit sd your powder charge is good, as stated already start seating deeper you will find a node however it may not shoot those bullets any better than your doing and it’s possible you may not get the accuracy that you have in your mind your going to get, despite what your wanting to do with it going off what you said in another thread the gun may not be capable of it keep that in mind so you don’t get to frustrated.
Wayne

 

[Ccrider]

I just can’t get past “crimp my neck with pliers.”

 

[AbeS]

I just can’t get past “crimp my neck with pliers.”

On gauge cases you understand that’s not ammo right?

 

[bozo699]

I just can’t get past “crimp my neck with pliers.”

I think he was trying to find jam length by slightly deforming the neck to hold a bullet in a empty case

 

[AbeS]

AbeS,
If you have single digit sd your powder charge is good, as stated already start seating deeper you will find a node however it may not shoot those bullets any better than your doing and it’s possible you may not get the accuracy that you have in your mind your going to get, despite what your wanting to do with it going off what you said in another thread the gun may not be capable of it keep that in mind so you don’t get to frustrated.
Wayne

Good advice I understand. I just feel that if I could get my ar in 6.5 grendel to shoot .52 moa it should be possible to get sub or at least 1 moa with this nice browning.

 

[dthomas]

Bczs has it right just seat deeper until you find a node

 

[ParallaxFree]

I’m very interested to know how the experienced get their coal. I have managed to get a sd of 8 for my browning bar in 30-06 but the 5 shot group was weak (1.5moa)

With an SD of 8 and a 1.5" five shot group, you're doing reasonably well for a semi-auto with a difficult trigger, mediocre at best factory barrel, an action not conducive to accuracy and a forearm imparting all kinds of random pressures and vibration as the bullet is on it's way.

At near maximum magazine length OAL, I don't think you have much to gain by experimentation with seating depth. I would suggest finding a gunsmith to improve the trigger and perhaps free float the forearm. Then you can experiment with various torque settings on the forearm screw at the range. If you get those rifle tuning things in line, then perhaps a little more load development will bring you down nearer to MOA.

Keep in mind, as these types of rifles get hot at the range, they start throwing shots all over the place. If you're going to do tuning and load development that's meaningful, you've got to keep the heat down by resting it between groups. When I work with this type of gun (and I have), it's best to take two or three other firearms along to shoot while you've got your Browning BAR cooling in the shade between three shot groups. I'm telling you from experience, if you get that gun all heated up, your tuning and load changes are going to be random, unrecognizable and non-repeatable with a cold/cool bore.

 

[RegionRat]

@AbeS , I agree with the others. You would be better off not trying to seat to longer than magazine length.

In a hunting situation it can add to your stress level and it is better to focus on the stalk and shot than oddities with your ammo.

The advice to double check your neck tension for effects from the feed and magazine versus the neck tension is also important for these Browning BAR rifles.

Here is a little nightstand reading fodder that will make you feel at ease about seating a little deeper if you are not used to the idea. The chambers of many classic hunting rifles were produced with long jumps in mind and that can go against some common "chase the lands" concepts. There is certainly a place for exploring the performance of a jammed or close to the lands recipe, but the Browning BAR isn't that place.

https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

That article is part of a series of a few that talk about how some bullet designs like to jump as much as they like to be jammed. Keep this wisdom in mind for some day when you have a match bolt gun on the drawing board.

If this particular rifle frustrates you after you try some alternate seating depths, you may want to consider one of the options above like the bedding or to have the HOTS system added. Every now and then, one of these barrels just doesn't shoot tight no matter what you feed it. Within the typical killing distance of a 30-06, you can still get the job done on pig/deer/elk/bear sized targets with a 1.5 MOA rig, as long as the POI is trustworthy.

 

[bozo699]

@AbeS , I agree with the others. You would be better off not trying to seat to longer than magazine length.

In a hunting situation it can add to your stress level and it is better to focus on the stalk and shot than oddities with your ammo.

The advice to double check your neck tension for effects from the feed and magazine versus the neck tension is also important for these Browning BAR rifles.

Here is a little nightstand reading fodder that will make you feel at ease about seating a little deeper if you are not used to the idea. The chambers of many classic hunting rifles were produced with long jumps in mind and that can go against some common "chase the lands" concepts. There is certainly a place for exploring the performance of a jammed or close to the lands recipe, but the Browning BAR isn't that place.

https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

That article is part of a series of a few that talk about how some bullet designs like to jump as much as they like to be jammed. Keep this wisdom in mind for some day when you have a match bolt gun on the drawing board.

If this particular rifle frustrates you after you try some alternate seating depths, you may want to consider one of the options above like the bedding or to have the HOTS system added. Every now and then, one of these barrels just doesn't shoot tight no matter what you feed it. Within the typical killing distance of a 30-06, you can still get the job done on pig/deer/elk/bear sized targets with a 1.5 MOA rig, as long as the POI is trustworthy.

Very well put
Wayne

 

[AbeS]

@AbeS , I agree with the others. You would be better off not trying to seat to longer than magazine length.

In a hunting situation it can add to your stress level and it is better to focus on the stalk and shot than oddities with your ammo.

The advice to double check your neck tension for effects from the feed and magazine versus the neck tension is also important for these Browning BAR rifles.

Here is a little nightstand reading fodder that will make you feel at ease about seating a little deeper if you are not used to the idea. The chambers of many classic hunting rifles were produced with long jumps in mind and that can go against some common "chase the lands" concepts. There is certainly a place for exploring the performance of a jammed or close to the lands recipe, but the Browning BAR isn't that place.

https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

That article is part of a series of a few that talk about how some bullet designs like to jump as much as they like to be jammed. Keep this wisdom in mind for some day when you have a match bolt gun on the drawing board.

If this particular rifle frustrates you after you try some alternate seating depths, you may want to consider one of the options above like the bedding or to have the HOTS system added. Every now and then, one of these barrels just doesn't shoot tight no matter what you feed it. Within the typical killing distance of a 30-06, you can still get the job done on pig/deer/elk/bear sized targets with a 1.5 MOA rig, as long as the POI is trustworthy.

Great advise thanks!