Cartridge Bearing Gauges - Introduction
Cartridge chamber gauges are used to check the dimensional accuracy of the cartridge chamber during the manufacture of weapons or barrels, during reworking or modification work and during official firing. The basis for the manufacture of gauges are the dimension tables of the BWaffG, the C.I.P. data sheets as well as dimensions according to the publications of SAAMI or according to customer specifications.
The production is carried out on modern CNC machine tools with additional observance of the specifications of German and European standards published for gauge production. The gauges for testing the locking distance are manufactured and offered as double gauges min/max (go/no-go). The final inspection of the gauges is carried out with a computer-controlled optical coordinate measuring machine, which is also available for contract measurements of customer gauges.
Dimensional principles for cartridge bearing gauges
The company Triebel Waffenwerkzeuge has been a competent partner for many decades when it comes to cartridge bearing gauges and their technical design.
In principle, the specifications of the Permanent International Commission for the Testing of Small Arms, or C.I.P. for short, are authoritative.
Unfortunately, it has also been known for many years that the data published by the C.I.P. are often incorrect.
However, due to the complex and ponderous structures of C.I.P., reliable correction of such errors in a reasonable time has rarely been possible.
As a partner of industry and trade, with corresponding competence in the field of cartridge and stock dimensions, the company Triebel Waffenwerkzeuge has in the past always pointed out such errors in the official channels and, for the good of the industry, offered to assist in correcting them. However, a structural solution to the basic organizational problems of the C.I.P., with the aim of providing the industry with reliable and usable data, has failed to materialize to date.
However, since our customers are urgently in need of an exact and practical design of cartridge bearing gauges, the original caliber data of the C.I.P. are always extensively checked, mathematically adjusted and, if necessary, corrected accordingly at Triebel Waffenwerkzeuge, and the dimensions are extended by the number of decimal places necessary for professional gauge production.
This elaborate work is the basis for an in-house caliber database that is probably unique in the world in terms of quality and scope.
The logical consequence of the data corrections is that certain nominal dimensions of individual Triebel gauges deliberately deviate from the C.I.P. specifications. This results accordingly from compliance with the exactly calculated dimensions after data correction.
For the purpose of tracing the data, gauges affected by this will be marked with the status "CIP+" by laser engraving and in the associated measurement report from the beginning of 2023. CIP+ means that the so-called basic dimensions of the C.I.P dimension sheets are complied with, but the dimensions derived from them may deviate.
For professional gauge management and dimensional control of cartridge bearing gauges, it is therefore advisable to always adopt the nominal values from the measurement record of the factory test. This avoids misunderstandings and ensures that the corresponding gauge is suitable for the intended test application.
In individual cases, you can receive information on a specific gauge by email upon request. Please contact us via info@triebel-guntools.de, if possible stating the article and serial numbers of the respective gauges.
Gauges for rifle cartridge bearing
Shoulder gauges for rifle cartridge bearing
This gauge checks the minimum depth L1 and L2 and thus the position of the shoulder. If the shoulder depth is correct, it must be possible to close the bolt of the gun when the minimum shoulder gauge is inserted. The position of the shoulder corresponds to the minimum dimensions. If a cartridge with shoulder has neither rim nor girdle, the shoulder gauge is the breech distance gauge.
The gauge is manufactured in minimum and maximum versions. They are always used in pairs. The dimensions are intended for weapons with cylinder breech. For self-loading weapons and for break-barrel weapons, there are partly deviating dimensions. Gauge sets with graduations of e.g. 0.02mm are optionally available in order to be able to determine the breech distance exactly.
This gauge checks the maximum depth L1 and L2 and thus the position of the shoulder If the bearing depth is correct, it must not be possible to close the bolt of the gun when the maximum shoulder gauge is inserted. The position of the shoulder corresponds to the maximum dimensions. If a cartridge with shoulder has neither rim nor girdle, the shoulder gauge is the breech spacing gauge. The gauge is manufactured in minimum and maximum versions.
They are always used in pairs. The dimensions are intended for weapons with cylinder breech. For self-loading weapons and for break-barrel weapons, there are sometimes different dimensions. (See SL Delta). Gauge sets with graduations of e.g. 0.02mm are optionally available to be able to accurately determine the breech distance.
This gauge checks the minimum depth of the cartridge chamber in the center of the shoulder. If the chamber depth is correct, it must be possible to close the bolt of the gun with the minimum shoulder gauge inserted. The length to the shoulder corresponds to the minimum dimensions.
Since all Weatherby cartridges have a belt, the breech distance is measured at the belt. The special shape of the gauge results from the large radii typical of all Weatherby cartridges. The gauge is manufactured in minimal design only.
For a whole series of cartridges of U.S. origin, the maximum length dimensions of the cartridge exceed the minimum length dimensions of the chamber. Particularly in the case of break-barrel guns, which are not very widespread in the USA, it happens in these calibers that the bolt of the gun cannot be closed, although the cartridge and the chamber comply with the prescribed dimensions.
To solve this problem, CIP added these dimensions "delta" to the length of the cartridge bearings. The cartridge bearings can therefore be manufactured longer by this difference. To check these dimensions, there are the "Delta" gauges, which are manufactured longer by this difference. This gauge checks the minimum depth L1 and L2 + "Delta" and thus the position of the shoulder If the bearing depth is correct, it must be possible to close the bolt of the gun when the minimum shoulder gauge is inserted.
Rim gauges for rifle cartridge bearing
These gauges check the minimum depth or maximum depth of rim milling of rifle cartridge bearings. Checking the rim depth is important for the breech spacing tolerance.
When the rim depth is correct, it must be possible to close the breech of the gun minimally with the rim gauge inserted; when using the maximum rim gauge, it must no longer be possible to close the breech. The gauge is manufactured in minimum and maximum versions. They are always used in pairs.
Case neck gauge minimal for rifle cartridge layer
This gauge checks the minimum depth of the case neck L3 and the diameter H2. If the depth / diameter is correct, it must be possible to close the bolt of the gun when the gauge is inserted. The length L3 and the diameter H2 correspond to the minimum dimensions. The gauge is manufactured in minimum dimensions only. This gauge is only inserted when the breech distance has already been checked and is correct.
The test only serves to check the minimum diameter and the minimum depth of the sleeve neck. If the gauge jams, the diameter of the case neck area is too small. As a rule, the gauge on shoulder cartridges will go deeper into the chamber than flush because the case neck on reamers is usually a little oversize in length. This is for safety and to compensate for wear, which is highest here. Due to the usually existing chamfer at the sleeve mouth, oversize in diameter results in a further increase in length. A case neck that is too short can jam the bullet and lead to increased gas pressure.
Belt gauges for rifle cartridge bearing
This gauge checks the minimum depth E and thus the depth of the belt gapping. If the bearing depth is correct, it must be possible to close the bolt of the gun with the minimum belt gauge inserted. The depth of the belt gouge corresponds to the minimum dimensions.
If a cartridge has a belt, the belt gauge is the breech distance gauge. The gauge is manufactured in minimum and maximum versions. They are always used in pairs.
This gauge checks the maximum depth E and thus the depth of the belt recess. If the bearing depth is correct, it must not be possible to close the bolt of the gun when the maximum belt gauge is inserted. The depth of the belt gouge corresponds to the maximum dimensions.
If a cartridge has a belt, the belt gauge is the breech distance gauge. The gauge is manufactured in minimum and maximum versions. They are always used in pairs.
Transition gauges for rifle cartridge bearing
This gauge checks the minimum depth E and thus the depth of the belt gapping. If the bearing depth is correct, it must be possible to close the bolt of the gun with the minimum belt gauge inserted. The depth of the belt gouge corresponds to the minimum dimensions.
If a cartridge has a belt, the belt gauge is the breech distance gauge. The gauge is manufactured in minimum and maximum versions. They are always used in pairs.
Powder chamber gauge for rifle cartridge chamber
This gauge checks the diameters P1 and P2' of the cartridge bearing. The diameters correspond to the minimum dimensions of the cartridge bearing. The gauge is only manufactured in minimum version. The powder chamber gauges for cartridge bearings of rimless cartridges have an extractor groove, the gauges for the cartridge bearings of rim cartridges are provided with a rim.
Since this edge is thinner than the cartridge cases, it is very sensitive! In order to avoid break-out with tilting barrel guns, the gauge can be beveled at one point. (Option) Because of the very small angles, the powder chamber gauge must not be pressed forcibly into the cartridge chamber. The gauge would jam. It must then, in order to avoid breaking off the edge of the gauge or damaging the extractor, be carefully pushed out with a cleaning rod.
Gauges for shot cartridge bearing
These gauges check the minimum depth or the maximum depth of the rim milling of shotgun shell bearings. Checking the rim depth is important for the breech tolerance, which is 0.20mm for break-barrel guns and 0.35mm for self-loading guns.
When the rim depth is correct, it must be possible to close the breech of the gun minimally with the rim gauge inserted; when using the maximum rim gauge, it must no longer be possible to close the breech. The gauge is manufactured in minimum and maximum versions. They are always used in pairs.
This gauge tests the minimum depth of shotgun shell bearings.
If the bearing depth is correct, it must be possible to insert the depth gauge at least up to the corresponding marking. The gauge is manufactured in minimum and maximum versions.
The diameter as well as the lengths correspond to the minimum dimensions. The gauge shows the minimum depth for all lengths of the respective caliber.
This gauge checks the maximum depth L at the minimum reference diameter H of shotgun shell bearings. If the bearing depth is correct, the depth gauge may be inserted no further than the corresponding marking. The lengths correspond to the maximum dimensions according to CIP. The diameter H corresponds to the minimum dimension according to CIP. The fact that the diameter H corresponds to the same dimension for both the minimum and maximum depth gauges makes it possible to compare the depth (bearing length). If the diameter H for the maximum depth gauge also corresponded to the maximum values, the reference point as the contact surface for the gauge would logically shift. Therefore, the traced length values would no longer be comparable with the values of the minimum gauge. The gauge shows the maximum depth L for all lengths of the respective caliber at minimum diameter H.
Gun cartridge bearing gauges
Shoulder gauges for pistol cartridge bearing
This gauge checks the minimum depth L1 and L2 and thus the position of the shoulder. If the shoulder depth is correct, it must be possible to close the bolt of the gun when the minimum shoulder gauge is inserted. The position of the shoulder corresponds to the minimum dimensions. The gauge is manufactured in minimum and maximum versions. They are always used in pairs. Gauge sets with increments of e.g. 0.02mm are available as an option in order to be able to determine the breech distance precisely.
This gauge checks the maximum depth L1 and L2 and thus the position of the shoulder If the bearing depth is correct, it must not be possible to close the bolt of the gun when the maximum shoulder gauge is inserted. The position of the shoulder corresponds to the maximum dimensions. The gauge is manufactured in minimum and maximum versions. They are always used in pairs. Gauge sets with increments of e.g. 0.02mm are available as an option in order to be able to accurately determine the breech distance.
Rim gauges for pistol cartridge chamber
These gauges check the minimum depth or maximum depth of rim milling of pistol cartridge bearings. Checking the rim depth is important for the breech spacing tolerance.
When the rim depth is correct, it must be possible to close the breech of the gun minimally with the rim gauge inserted; when using the maximum rim gauge, it must no longer be possible to close the breech. The gauge is manufactured in minimum and maximum versions. They are always used in pairs.
Case mouth gauges for pistol cartridge bearing
This gauge checks the minimum depth L3 of the cartridge chamber. If the chamber depth is correct, it must be possible to close the gun's bolt when the minimum breech distance gauge is inserted. The length of the cartridge chamber gauge corresponds to the minimum dimensions. If the cartridge has neither rim nor shoulder, the L3 gauge is the breech spacing gauge. The gauges are manufactured in minimum and maximum versions. They are always used in pairs.
This gauge checks the maximum depth L3 of the cartridge chamber. If the chamber depth is correct, it must not be possible to close the gun's bolt when the maximum bolt gap gauge is inserted.
The length of the cartridge bearing gauge corresponds to the maximum dimensions. If the cartridge has neither rim nor shoulder, the L3 gauge is the breech spacing gauge. The gauges are manufactured in minimum and maximum versions. They are always used in pairs.
Transition gauges for pistol cartridge bearing
This gauge checks the minimum depth of the transition cone If the depth is correct, it must be possible to close the gun bolt when the gauge is inserted. The dimensions of the gauge correspond to the minimum dimensions. The gauge is manufactured in minimum design as standard.
Two basic transition types are distinguished:
1. Cone only
2. Cone with cylindrical part
For transitions consisting of a cone with a cylindrical part, it must be ensured that the gauge does not jam in the cylindrical part. This would result in incorrect measurement. Due to the very small angles, the transition gauge must not be forced into the cartridge bearing. The gauge would jam. It must then be carefully pushed out with a cleaning rod to avoid breaking off the edge of the gauge or damaging the extractor.
Powder chamber gauges for gun cartridge chambers
This gauge checks the diameters P1 and P2' of the cartridge bearing. The diameters correspond to the minimum dimensions of the cartridge bearing. The gauge is only manufactured in minimum version. The powder chamber gauges for cartridge bearings of rimless cartridges have an extractor groove, the gauges for the cartridge bearings of rim cartridges are provided with a rim. Since this rim is thinner than that of the cartridge cases, it is very sensitive!
Because of the very small angles, the powder chamber gauge must not be forced into the cartridge chamber. The gauge would jam. It must then be carefully pushed out with a cleaning rod to avoid breaking off the edge of the gauge or damaging the extractor.