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Gibbs40
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breech seating questions
Sep 30th, 2014 at 8:10am
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Hi Guys ,I'm new to the forum so although i'v been shooting and reloading for a long time i hope you will forgive me if i ask some questions that you may think are pretty basic ,I want to learn about breech seating ,and i would really appreciate some help and advice .Also to get a bullet design for my needs so i can have a custom bullet mould made . A bit of background info might help you to see my problem ,about 18 months ago i bought a Pedersoli 1885 hi wall classic model in 38/55 cal 1 in 12 twist cut with a chamber for the longer case and throated to facilitate breech seating [this according to Pedersoli's catalogue ].iI want to use smokeless powder and have been using a RCBS 378/312 bps and a LYMAN 2640674 330 gn bullet both fixed and breech seated .nowadays i'm shooting at 100/200 yds off the bench off a rest using an 8x scope and my groups are about 2 1/2''at 100 yds using an hard cast bullet and various powders .I did several barrel casts and believe the groove diam is  .3805/381 [Pedersoli's stated groove diam  is .378] my moulds cast .378 so i think thats a problem [bullets cast at about 30/1 are not stable and keyhole ] A slug .381  loaded in a case and chambered is i think a little too tight .The above problems have lead me to breech seat the bullets mentioned using a plugged case   ,and have shown a little  improvement, but because the bullets are cylindrical and when cast with a fairly hard alloy only allow engraving the first two driving bands even when pushed in quite hard .This is why i'm thinking about using a tapered bullet and having a custom mould made ,and advice about a bullet design and dimensions would be greatly appreciated .I know i have given you guy's a lot to think about but you have a depth of knowledge that does not exist anywhere else ,,kind regards  Gibbs /40
  
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40_Rod
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Re: breech seating questions
Reply #1 - Sep 30th, 2014 at 9:01am
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First make a good casting from the transition to throat and about an inch the rifling. That and the twist will give you all the dimensions that a good custom mold maker will need. 
Second get rid of that hard alloy. I would start with 25 : 1 lead tin. Alloys like linotype and such are way too hard to give good accuracy with breech-seated bullets. 
  Start out with your bullet seated about 1/16” ahead of the case breech-seat a lubed bullet and push it out and look at it you should be able to see that the base is sealing the chamber off so there will be no gas cutting when a round is fired. 
  This should get you started after you get some decent groups you can adjust the load and seating depth until you get the best results.

40 Rod
  
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westerner
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Re: breech seating questions
Reply #2 - Sep 30th, 2014 at 7:53pm
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I breech seat very hard bore riding tapered bullets in my 40-65. Will score 250's loaded that way. Bullets are bore riding with the grease groove half tapered. Takes a stout breech seater to seat the bullets.   

For your rifle I would use Saeco tapered bullets cast 30-1 or 40-1 lead tin. Under size bullets can be very accurate. 

I shoot .376-7 diameter Hoch bullets in a rifle that measures .379.  At the Spokane match this spring put five shots in a nickel size group on one of my bench targets with iron sights. 

        Joe.
  

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Gibbs40
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Re: breech seating questions
Reply #3 - Oct 6th, 2014 at 3:19pm
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Hi Guys,

Thanks very much westerner and 40_Rod for your advice. I have made bore casts with cerosafe before but am weary of making a chamber cast because of the risk of the cast sticking in the chamber/throat as has happened to others. I think that if I can obtain a mould that will cast a bullet with base bands groove diameter (+001?) that a bullet of softer alloy may be a better bet. Though different shooters seem to have different opinions. I am looking for a breech seat design bullet for 300/320 gns. If anyone can help please can you advise. Regards
  
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frnkeore
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Re: breech seating questions
Reply #4 - Oct 6th, 2014 at 3:43pm
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If you can give me the bore size to go along with the groove, I'll rework one of my 38 cal, BS designs to fit your barrel.

Frank
  

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Re: breech seating questions
Reply #5 - Oct 6th, 2014 at 4:04pm
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Try soft lead. Under size bullets will bump up to fill the bore. Use a fast powder like IMR 4227, 4759, LilGun. AA#9.  Might be surprised how well it shoots.    The Saeco #571 is a very good bullet and close to your groove diameter.

           Joe.
« Last Edit: Oct 6th, 2014 at 4:16pm by westerner »  

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Gibbs40
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Re: breech seating questions
Reply #6 - Oct 9th, 2014 at 8:33am
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Hi Joe and Frank ,thanks for your advice ,Joe i thought like  you that it might be a good idea to try a softer bullet with a fairly quick powder ,but so far they have all resulted in poor accuracy ,i don't think the bullets bump up enough to seal the bore and take the rifling .Groups show a lot of vertical dispersion and some key holeing ,thanks also  for the info about the saeco #571..
Hi Frank ,thanks for your offer to rework one of your 38 cal BS  designs , that would be most helpful , the bore diameter is as near as i can measure it .3745/.375 hope this helps ,
thanks again for your help ,regards ,,   
  
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Re: breech seating questions
Reply #7 - Oct 9th, 2014 at 12:39pm
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Copy this drawing and send it to a mold maker. It's a nice and safe design based on the Ron Long and Paul Jones, tapered bullets.

Frank
  

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Re: breech seating questions
Reply #8 - Oct 9th, 2014 at 7:00pm
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Gibbs40, around the time when the 12 twist Pedersoli highwalls first came out a review was written in Steve Garbe's publication ( the Black Powder Cartridge News ).  A number of bullets were tried and some excellent results were obtained.  If you like I can find the issue number.  It might help you get that rifle sorted out.

Chris.
  
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Re: breech seating questions
Reply #9 - Oct 10th, 2014 at 9:38am
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Essential that you know the bore and groove diameter with a high degree of accuracy before committing to a custom mould.   

If you follow the directions, you should not have a problem with cerrosafe--I never leave the cast in the chamber as long as they say.  If you do happen to stick a cast in the chamber, it's not the end of the world; just heat the chamber area gradually with a propane torch, with the barrel pointed downward, until the cerrosafe runs out.  Don't ask me how I know.  Since the melting point is less than 200 degrees, you don't need to get anything hot enough to damage it (obviously, remove the buttstock and forearm before doing this).

From what you said, the bullet either needs to be ~0.380" diameter or you need to neck-turn cases for fixed ammo, so I can see where you are leaning to breech-seating.  It looks like the bullet in the drawing should work if cast 1:20 or so.  Be aware that a bullet even slightly oversized is somewhat harder to breech-seat with 1:20 than 1:30.

Clarence
  
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Gibbs40
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Re: breech seating questions
Reply #10 - Oct 11th, 2014 at 4:06am
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Good morning Frank ,thanks for sending me that design for the breech seat bullet ,i intend to do as you advise and send a copy to a custom mould maker , i have a question thats also touched on by Clarence , will i require a mechanical breech seater or do you think  a push seater will do the job ?I have a vintage target scope fitted to my hi wall so there's not much space to work with ,regards  Gibbs 40 .Hi Clarence , good to talk to you ,thanks for your advice about the cerrosafe i have to admit to being a bit windy about making a chamber cast so i have slugged the bore from the breech end with a soft lead slug tapped in and then back out ,i know it doesn't give me the detail of a cast but it has confirmed that when measured it is very similar to my muzzle casts ,also i think the bullet diameter should be closer to .382 .I have considered case neck turning because of the oversize bullets ,but wanted to try breech seating ,,kind regards   Gibbs 40  .Good morning Chris , thanks for your help , if you could send me the issue number of bpcn i would be very grateful ,though i may not have access to all copies of the bpcn on this side of the pond ,also if anyone is interested i am posting a new topic in the general section of the forum asking about other peoples experiences with the 1 in 12 Pedersoli Hi Walls ,to everyone my thanks   ,and keep well    regards   Gibbs 40
  
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Re: breech seating questions
Reply #11 - Oct 11th, 2014 at 11:07am
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Gibbs40,   I just had a look on SPG's web site and the issue is #74, Summer 2011.    It's still available as a reprint. The article title is "Reloading Bench: High Wall .38-55 Target Rifle from Davide Pedersoli." and is 5 pages long.   It's a well written article.  I did a little bit of reading on these rifles as I was considering buying one a few years ago.   I ended up buying another C. Sharps highwall instead as I've got a few of them already.

BTW, should you go the route of breech seating, I'd consider a Russ Weber breech seater.   
 
Chris.
  
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Re: breech seating questions
Reply #12 - Oct 11th, 2014 at 1:23pm
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Quote:
Good morning Frank ,thanks for sending me that design for the breech seat bullet ,i intend to do as you advise and send a copy to a custom mould maker , i have a question thats also touched on by Clarence , will i require a mechanical breech seater or do you think  a push seater will do the job ?I have a vintage target scope fitted to my hi wall so there's not much space to work with ,regards  Gibbs 40


I believe that you would need a mechanical breech seater for my design unless you rethroat the chamber. Rechambering with a.403 - .404 straight neck and a freebore throat with a long leade would fix all your problems and allow the use of a push seater. Even so, a mechanical BSer won't be a waste.

Frank
  

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Re: breech seating questions
Reply #13 - Oct 12th, 2014 at 11:45am
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Hi Chris , thanks for the info for issue #74 of bpcn  ,i will be doing my best to get a copy ,if you look at my post in the general topic section of this forum you may well think you made a good choice ,though i do believe i will end up with a good shooting rifle in the end ,,regards ,,Gibbs 40
   

Hi Frank ,thanks for your technical input re breech seating , for the moment i have asked a mould maker to make me a mould  from the design you sent to me ,i hope this will take me a little closer to getting the accuracy potential from this rifle ,will let you know how i progress  ,  regards ,Gibbs 40
  
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Re: breech seating questions
Reply #14 - Oct 16th, 2014 at 5:17am
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I use a 375gn Paul Jones bullet that is the 38001 Creedmore modified in size to a chamber cast of the chamber/throat area that I sent him.

The nose is .371", 1st and 2nd driving band .373", 3rd .377", and the 4th and base are .380", when cast 1:30 alloy.

With this combination the nose rides the top of the lands and because the Hiwall has a camming action, bands 1 & 2 get driven into the rifling. If I load a round and extract it the bullet then needs to be gently tapped out with a soft rod. Cases are not cripmed and are indexed the same for each shot.

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