Prosecution Insights
Last updated: April 19, 2026
Application No. 17/941,894

FIREARM BARREL WITH NON-METAL OUTER SLEEVE

Non-Final OA §102§103
Filed
Sep 09, 2022
Examiner
GOMBERG, BENJAMIN S
Art Unit
3641
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
BLACKSTONE FIREARMS, LLC
OA Round
3 (Non-Final)
66%
Grant Probability
Favorable
3-4
OA Rounds
2y 7m
To Grant
96%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allow Rate
341 granted / 513 resolved
+14.5% vs TC avg
Strong +30% interview lift
Without
With
+29.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
27 currently pending
Career history
540
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
39.4%
-0.6% vs TC avg
§102
27.1%
-12.9% vs TC avg
§112
31.2%
-8.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 513 resolved cases

Office Action

§102 §103
DETAILED ACTION In the Final Rejection mailed 6/26/2025: Claims 1-18 and 21 were withdrawn. Claims 19-20 were rejected. Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/18/2025 has been entered. Information Disclosure Statement The information disclosure statement (IDS) submitted on 12/18/2025 is being considered. However, some of the references in the IDS were not considered (denoted by being lined through) for failing to comply with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. Response to Amendment The amendment to the claims filed 12/18/2025 has been entered: Claims 22-25 are new. Claims 1-25 are active. Claims 1-18 and 21 are withdrawn. Response to Arguments Applicant's arguments filed 12/18/2025 have been fully considered but they are not persuasive. In response to applicant’s argument that the claimed invention teaches away from Adolphsen and Newman because the references do not disclose the features which are now claimed (specifically, that the bushing sleeve is adapted to be slidably engaged with a raised coupler section of the barrel, and that the bushing sleeve slidably carries an independent gas block), the examiner respectfully disagrees, and a showing of how each of the features is disclosed by Adolphsen and/or Newman is provided below. The examiner notes that the preamble of the claim(s) is not considered a limitation and is of no significance to claim construction. See Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1305, 51 USPQ2d 1161, 1165 (Fed. Cir. 1999). See MPEP § 2111.02. Additionally, the examiner notes that a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. Claim Objections Claim(s) 19 is/are objected to because of the following informalities: Regarding claim 19, the word “a” should be inserted before “first diameter” in line 2. Appropriate correction is required. Claim Rejections - 35 USC § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 19-20 and 23 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Adolphsen (US 2013/0036902), herein referenced ‘Adolphsen’. Regarding claim 19, Adolphsen discloses a bushing (Fig. 13) for use in a firearm barrel assembly, the firearm barrel assembly comprising a barrel tube (150; Fig. 12) having a first diameter (Fig. 12; diameter of barrel tube 150 at grooves 100a-d) and a raised coupler section (Fig. 12; portion of barrel tube 150 with barrel gas port 152) having an outer diameter greater than said first diameter (Fig. 12; the diameter of barrel tube 150 at the location of barrel gas port 152 is shown to be greater than the diameter of barrel tube 150 at the location of any of the grooves 100a-100d) and a first non-metal sleeve (154; par. 48) and a second non-metal sleeve (166; par. 48) concentrically spaced apart from said barrel tube (Figs. 13A-13B) and forming an air gap therebetween (Fig. 13B; par. 65-66; rear void 156 and front void 168 define an air gap between first sleeve 154, second sleeve 166, and barrel tube 150 prior to being filled with filler material), the bushing comprising: a bushing sleeve (160) having: an inner diameter (Figs. 13A-13B); a bushing sleeve outer diameter (Fig. 13A; par. 66; outer diameter of central portion of gas elbow 160 to which gas block 21 is attached); a first end (162) having a first reduced diameter (Fig. 13A; par. 66), said first reduced diameter less than said bushing sleeve outer diameter (Fig. 13A; par. 66); and a second end (164) having a second reduced diameter (Fig. 13A; par. 66), said second reduced diameter less than said bushing sleeve outer diameter (Fig. 13A; par. 66); wherein said bushing sleeve is adapted to be slidably engaged with said raised coupler section (Fig. 13B; par. 68). Regarding claim 20, Adolphsen discloses wherein said bushing sleeve provides constant pressure between said barrel tube and said first and said second non-metal sleeves when said barrel assembly is in use (Fig. 13B; par. 65-66). Regarding claim 23, Adolphsen discloses a bushing gas escape hole (168) through said bushing sleeve and adapted to be communicatively coupled to a gas escape hole (152) through said barrel tube (par. 66). Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claim(s) 22 and 24-25 is/are rejected under 35 U.S.C. 103 as being unpatentable over Adolphsen (US 2013/0036902) as applied to claim 19 above, and further in view of Newman (US 2018/0023913), herein referenced ‘Newman’. Regarding claims 22 and 24, Adolphsen discloses wherein said bushing sleeve carries a gas block (21) comprising a gas block gas escape hole (Figs. 13A-13B; par. 66), wherein said bushing sleeve further comprises a bushing gas escape hole (168) through said bushing sleeve and adapted to be communicatively coupled to a gas escape hole (152) through said barrel tube (par. 66), and wherein said bushing gas escape hole is communicatively coupled to said gas block gas escape hole (Figs. 13A-13B; par. 66), but does not expressly teach wherein said bushing sleeve slidably carries an independent gas block (21). Newman teaches a firearm barrel assembly (10) comprising a non-metal sleeve (13) arranged concentrically to a barrel tube (11), wherein one or more gas key inserts (16) are joined to the barrel tube (par. 38), and wherein a gas block (20) is joined to the one or more gas key inserts (Figs. 8-10) by a threaded fastener inserted through a hole in the gas block and threaded into a fastening hole of the one or more gas key inserts (Fig. 10; par. 38) which is aligned with a barrel clearance hole in the barrel tube (Fig. 4), such that the one or more gas keys act as a solid platform for mounting the gas block (claim 1). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for the gas block of Adolphsen to be independent of the bushing sleeve as taught by Newman with a reasonable expectation of success in order to fit the barrel assembly with a gas block to be utilized by the firearm (Newman; par. 38) in a removable manner, while still preventing gas from leaking into the composite (Newman; par. 38). Regarding claim 25, Adolphsen discloses a fastening hole (178) extending through said bushing sleeve (Figs. 13B; par. 68) and adapted to align with a barrel clearance hole (Figs. 13B-14), but does not expressly teach wherein the fastening hole is a threaded tap aligned with a barrel clearance hole extending partially through the barrel tube. Newman teaches a firearm barrel assembly (10) comprising a non-metal sleeve (13) arranged concentrically to a barrel tube (11), wherein one or more gas key inserts (16) are joined to the barrel tube (par. 38), and wherein a gas block (20) is joined to the one or more gas key inserts (Figs. 8-10) by a threaded fastener inserted through a hole in the gas block and threaded into a fastening hole of the one or more gas key inserts (Fig. 10; par. 38) which is aligned with a barrel clearance hole in the barrel tube (Fig. 4), such that the one or more gas keys act as a solid platform for mounting the gas block (claim 1). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for the fastener of Adolphsen to be inserted into a gas block hole and threaded into the fastening hole of the bushing sleeve as taught by Newman with a reasonable expectation of success in order to fit the barrel assembly with a gas block to be utilized by the firearm (Newman; par. 38) in a removable manner, while still preventing gas from leaking into the composite (Newman; par. 38). Conclusion Claims 19-20 and 22-25 are rejected. Claims 1-18 and 21 are withdrawn. Prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BENJAMIN S GOMBERG whose telephone number is (571)272-4802. The examiner can normally be reached Monday - Friday 8:30 AM - 5:00 PM EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Troy Chambers can be reached on (571)272-6874. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Troy Chambers/Supervisory Patent Examiner, Art Unit 3641 /BENJAMIN S. GOMBERG/ Examiner Art Unit 3641
Read full office action

Prosecution Timeline

Sep 09, 2022
Application Filed
Oct 13, 2022
Response after Non-Final Action
Sep 20, 2024
Non-Final Rejection — §102, §103
Mar 13, 2025
Examiner Interview Summary
Mar 21, 2025
Response Filed
Jun 23, 2025
Final Rejection — §102, §103
Dec 18, 2025
Request for Continued Examination
Jan 06, 2026
Response after Non-Final Action
Jan 09, 2026
Non-Final Rejection — §102, §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
66%
Grant Probability
96%
With Interview (+29.7%)
2y 7m
Median Time to Grant
High
PTA Risk
Based on 513 resolved cases by this examiner. Grant probability derived from career allow rate.

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